THE APPLICATION OF NONLINEAR PHONOLOGICAL THEORY
TO INTERVENTION WITH PHONOLOGICALLY DELAYED TWINS
By
MARIA VERENA VON BREMEN
B.A., The University of British Columbia, 1985
A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF
THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
in
THE FACULTY OF GRADUATE STUDIES
(School of Audiology and Speech Sciences)
We accept this thesis as conforming
to the required standard
THE UNIVERSITY OF BRITISH COLUMBIA
September 1990
© Maria Verena von Bremen, 1990
ii
ABSTRACT
Despite the fact that speech-language pathologists do not develop the theories
underlying the principles and procedures used in the clinic, speech and language clinicians
are ethically obliged to apply the "best" possible theory in their practice. Recently
phonologists have been developing a theory of nonlinear phonology. Application of this
theory to cross-linguistic data and to child language data has shown that what appeared
to be idiosyncratic or difficult to account for using previous theoretical formulations can be
neatly explained using a nonlinear phonological explanation.
The purpose of this study was to investigate the possibility of further extending
the application of nonlinear phonological principles to the field of speech-language
pathology. Two levels defined by the theory, segmental and prosodic, were investigated
in a six-month-long intervention programme with a set of phonologically delayed twins
(aged 5;6 at the outset of the project). Each twin was assigned to an experimental
condition motivated by one of these levels, or tiers. In each condition, intervention goals
were determined by parameters of the theory; the segmental condition contrasted
features "higher" versus "lower" in the feature hierarchy, while the prosodic condition
contrasted moraic with onset-rime descriptions of syllable/word shape. Using twins as
subjects also allowed the twin aspect of language acquisition and speech-language
intervention to be explored.
Results of the phonological intervention study revealed that nonlinear phonology
provides a viable framework for assessing and determining goals for phonological
remediation. A comparison of progress in therapy indicated that one twin acquired
therapy goals faster than the other. An investigation of the differential progress of the
twins allowed conclusions to be drawn regarding social awareness and success in
phonological therapy.
iii
TABLE OF CONTENTS
ABSTRACT ii
LIST OF TABLES v
LIST OF FIGURES vi
ACKNOWLEDGEMENTS viii
CHAPTER 1. INTRODUCTION 1
CHAPTER 2. THE THEORY 6
Autosegmental Phonology 6
The Feature Geometry 11
Markedness 15
Underspecification 16
Prosodic Phonology 19
Syllables and Segments Combined 25
The Acquisition Process 27
CHAPTER 3. METHOD 29
Initial Assessment 29
Segmental Condition 31
Syllabic Condition 32
Therapy Schedule 33
Therapy Procedure 36
CHAPTER 4. THE SEGMENTAL CONDITION 38
The Starting Point '. 39
Determining Targets for Remediation 45
iv
Results 48
Conclusions 53
CHAPTER 5. THE SYLLABIC CONDITION 56
The Starting Point 58
Determining Targets for Remediation 60
Treatment , 63
Results 65
Conclusions 78
CHAPTER 6. TWINS AS RESEARCH SUBJECTS 81
Twins: Handicapped or Not? 81
Heredity versus Environment 83
Twin versus Co-Twin 84
Twins and Psychology 88
Speech and Language Therapy with Twins 90
Autonomous Language 92
Summary and Conclusions 93
CHAPTER 7. CONCLUSIONS 96
Comparison of Nonlinear Phonology and Phonological Process Theory for Intervention 98
Limitations of the Study 100
REFERENCES 102
APPEND DC 1: MINIMAL SPECIFICATIONS OF ENGLISH CONSONANTS 108
APPENDIX 2: GRAND PROBE WORD LIST 112
APPENDIX 3: GRAND PROBE DATA FOR BOTH SUBJECTS 115
APPENDIX 4: THERAPY SESSION OBJECTIVES FOR BOTH SUBJECTS 136
V
LIST OF TABLES
Table 1: Percentage accuracy achieved by Subject 2 for clusters targeted in therapy based on the moraic theory of syllable organization 65
Table 2: Percentage accuracy achieved by Subject 2 for clusters targeted in therapy based on onset-rime theory 65
Table 3: Percentage accuracy figures for the initial cycle of targeting /zf and /!/ 69
vi
LIST OF FIGURES
Figure 1: An example of feature columns for the word toe. based on Chomsky & Halle (1968) 7
Figure 2: SPE characterization of a nasal assimilation rule 9
Figure 3: Nonlinear representation of the Place Assimilation Rule 10
Figure 4: Example of the spreading of the PLACE of /k/ to the preceding nasal consonant 10
Figure 5: Example of a possible rule according to linear phonology which is impossible under nonlinear phonology (as described in McCarthy, 1988) 10
Figure 6: Adaptation of Sagey's (1986) feature geometry incorporating McCarthy's (1988) refinements and Clements' (1985) schematic representation 12
Figure 7: The hierarchical arrangement of the syllable as proposed by onset-rime theory (based on Pike & Pike, 1947) 20
Figure 8: The internal constituent structure of the syllable as proposed by moraic theory 23
Figure 9: Moraic representation of the syllable hierarchy for the
word pin 24
Figure 10: Summary of the design of one therapy block 34
Figure 11: Word-initial phonetic inventory of both subjects of this study 40
Figure 12: The syllable-initial-within-word phonetic inventory for both subjects of this study 40
Figure 13: The word-final phonetic inventory for both subjects of this study 40
Figure 14: The established feature hierarchy at the beginning of intervention for both subjects 42
vii
Figure 15: The twins' realizations of word-final /f/ (left) and word-final /0/ (right) with unestablished nodes marked in parentheses 44
Figure 16: The nonlinear specification of the feature changes required to realize /r/ as [w] 44
Figure 17: Graph of the segmental targets based on mini probe results for Subject 1 50
Figure 18: Graph of the segmental targets based on mini probe results for Subject 2 51
Figure 19: Graph of the syllabic targets based on mini probe results for Subject 2 70
Figure 20: Graph of the /s/-cluster data based on grand probe results for Subject 2 71
Figure 21: Graph of the /Cr/-cluster data based on grand probe results for Subject 2 73
Figure 22: Graph of the /Cl/-cluster data based on grand probe results for Subject 2 74
Figure 23: Graph of the syllabic targets based on mini probe results for Subject 1 77
A C K N O W L E D G E M E N T S
Many people have been involved with different stages of this project. I would
like to thank the twins and their parents for taking part in this study. The Vancouver
School Board was generous in making space and the subjects available to me. Many
thanks are due to Meredith Land, VSB Speech-Language Pathologist for her support
and suggestions during the therapy portion of the study.
Carolyn Johnson deserves more thanks than can be expressed here for
patiently reading and rereading drafts of this manuscript. Your encouragement
throughout this study and my masters programme were greatly appreciated. I would
also like to thank John Gilbert for volunteering to be a member of my examining
committee and for first introducing me to the field of speech-language pathology.
Many, many thanks go to my mentor, Barbara Bernhardt, for not only guiding
me throughout this project, but also for challenging and inspiring me at every stage.
I would like to thank my parents for their constant support throughout my
university years. And most of all, I would like to thank my husband, Jonathan
Oliphant. My appreciation of your understanding and support, especially during the
final stages of writing this paper, cannot be adequately expressed here.
1
CHAPTER 1
INTRODUCTION
The assessment and remediation of communication disorders requires that the
speech-language pathologist be able to draw on and integrate the facts and theories of
several academic disciplines. Physiology, psychology and linguistics name only a few
examples. It is impossible to make statements regarding the nature of a
communication disorder, nor how it should best be treated, without referring to at least
basic theoretical assumptions about language, its components, and how humans make
use of it for communication. The assessment and treatment of phonological disorders
presents no exception; clinicians rely on theories developed in the field of linguistics to
guide them in sampling, analyzing and describing the phonological disability of their
clients.
Currently, one of the most widely used phonological assessment procedures
evaluates a child's utterances for the number of phonemic contrasts which have, and
have not, been established in their phonological system. The usual result of this
evaluation is a description of the child's speech in terms of phonological processes.
Such processes were first proposed by Stampe (1969), a phonologist interested in
relationships between phonological theory, universals, historical change, and child
language acquisition. Stampe defines processes as mental operations which "merge a
potential phonological opposition into that member of the opposition which least tries
the restrictions of the human speech capacity" (Stampe, 1969:VII). According to this
view, processes are considered to be innate and, without any conscious input from the
child, just "happen" to simplify the adult form to one that the child's output mechanism
2
can manage. The role of phonological acquisition then, is to learn to suppress, limit or
reorder the application of these processes so that the child's output matches the sound
system of her native language. Of note here is the implicit assumption that the child's
underlying representation matches the adult form of a word.
A more recent view of phonological processes does not agree with Stampe's
initial assumptions. Specifically, processes are no longer considered to be entities
which apply to the utterances of a passive child. Instead, the child is viewed as
actively, though still not consciously, using them to simplify an underlying
representation in some relatively consistent way (Ingram, 1976). In addition, our
knowledge of the child's perceptual system is incomplete and therefore does not allow
us to assume that the underlying representation is adultlike as is implied by Stampe's
interpretation.
The rethinking of the theoretical assumptions of phonological processes, as
demonstrated by Ingram (1976), has attempted to align the language learner's task in
phonological acquisition with the more general task of language acquisition, in which it
is thought the child actively develops and tests hypotheses regarding the patterns of
his linguistic environment. The problem with such a reanalysis is that the theory
remains incomplete. The difficulty is that processes, at least in their present form, do
not have any psychological reality because we do not know the nature of the
underlying representations on which they are acting. The process "intervocalic
voicing," for example, can only be accepted as a descriptive statement rather than an
explanation of the surface representation, since we cannot know if constraints are
affecting the adult input or the child's output.
A further difficulty presents itself when the speech-language pathologist uses a
phonological process analysis in the clinic. There is nothing inherent in the theory
underlying the analysis, nor in the processes themselves, that guides the speech-
language pathologist in making decisions regarding which observed processes should
3
be targeted first in therapy.1 Several researchers have suggested that those
processes which have the most detrimental effect on the child's intelligibility should be
a priority for remediation (Grunwell, 1985; Leonard, 1985; Leinonen-Davies, 1988),
while others recommend that processes which disappear early in the acquisition
pattern of normal children should be eliminated first (Ingram, 1976; Grunwell, 1985).
Suggestions such as these provide the clinician with only general guidelines for
making decisions regarding treatment goals. It is often difficult to decide just which
processes are having the most detrimental effect on a child's communication. In
addition, decisions based on the patterns of normal children do not necessarily target
those segments whose acquisition will lead to the greatest communicative success.
Consequently, treatment decisions are ultimately left to the preferences of the
individual clinician rather than being motivated by theoretical principles of the
phonological process analysis.
Thus far, only the assumptions regarding the role of processes in phonological
acquisition have been considered. Inherent in any phonological assessment are
theoretical assumptions defining what constitutes a sound segment in the first place
and what its representation should look like. In this sense, processes are consistent
with the view first developed in the Sound Pattern of English (Chomsky & Halle,
1968), which holds that sounds are represented by bundles of features. These feature
bundles were developed to account for the sound changes and patterns observed in
the languages of the world. Recent work in phonological theory, however, has shifted
from a language rule-oriented approach to one more concerned with providing an
account of phonological representations. These representations are considered to be
"hypotheses about the structure of linguistic knowledge in the human brain" and, as
1 According to Stampe's (1969) view phonological processes are unordered in their application to an underlying representation.
4
such, are intended to explain how the mind represents the sound change rather than
just to describe it (Sagey, 1986:10). Instead of organizing linguistic utterances into
sequences of feature bundles, each representing a sound, current theory proposes that
the phonological components making up a word are arranged hierarchically. The
advantage of such an arrangement is that nonadjacent segments or features of
segments, whose interaction was formerly accounted for by postulating relatively ad
hoc transformation rules, are now considered to be adjacent because they fall on
adjacent limbs or nodes of a hierarchy. As a consequence, a language rule, or the
mind's representation of that rule, is considerably simplified, since the effect of one
segment need only transfer to the neighbouring segment. The "nonlinear" view of
phonology proposes that features are arranged into hierarchies to make up a segment,
and that segments in turn are organized into hierarchies to create syllables.
There is no question that speech-language pathologists should adopt the best
phonological theory available and apply it to their work. In this way, the best theory—
that is, the one that must come closest to being right—is the theory which accounts for
the greatest amount of language data in the most constrained way.2 Where
synchronic data (rather than historical change) is accounted for, the best theory should
also represent the workings of the human mind in arriving at the surface output. This
being the case, drawing on the best theory in order to determine goals and therapy
activities in the clinical setting should lead to the most rapid improvement of speech
and language because the procedures utilized present the material to be acquired in a
manner which mirrors the organization of language within the brain.
2 The arguments supporting this "best" theory, however, come from linguistics and not from speech-language pathology. Although clinical data does not provide the primary motivation for the theory, it may provide independent evidence supporting it.
5
The purpose of the research study described in the remainder of this paper,
then, was to evaluate the possibility and the advantages of applying a nonlinear
theory of phonology to the assessment and remediation of phonological disorders. The
second purpose focussed on the possibility of clinical data providing independent
support for this theory. This study was closely modelled after one by Bernhardt
(1990), who first evaluated nonlinear phonology from the clinical point of view. A set
of identical male twins with a moderately-severe phonological disorder served as the
subjects for the current study. It is hoped that their data will add to Bernhardt's data
and results, as well as to the limited body of phonological twin data.
The following chapter of this thesis presents the development and details of
nonlinear phonology. Chapter 3 outlines the methodology of the seven-month long
intervention programme. Chapters 4 and 5 then discuss the results of treatment from
a segmental and syllabic point of view. Chapter 6 compares the treatment results of
the two subjects and outlines possible explanations for the findings. Finally, chapter 7
presents my conclusions regarding the use of nonlinear phonology in the clinic, as well
as possible limitations of the study.
6
CHAPTER 2
THE THEORY
Current phonological theories find their starting point in the Sound Pattern of
English (Chomsky & Halle, 1968), henceforth SPE. Assumptions regarding the
ordering of rules, and the distinction between underlying and surface representations,
for example, have been maintained in present-day theories. Changes between current
nonlinear theory and SPE lie mainly in how the theory represents the relationship
between phonological components. SPE presented a linear view of phonology where
segments, composed of bundles of features, could be lined up one next to the other.
Nonlinear phonology presents a more constrained modular theory made up of distinct
but interacting subcomponents that account for stress, syllabification, and segmental
phonology (McCarthy, 1988). This current modular theory combines the research
findings of two independent theories which were being developed at about the same
time: autosegmental phonology (Leben, 1971, 1973; Goldsmith, 1976; Clements, 1976;
McCarthy, 1979) introduced the notion of multilinear representations, while metrical
phonology (Liberman, 1975; Liberman & Prince, 1977; Selkirk, 1980a; Hayes, 1981)
developed the idea of hierarchical representations.
Autosegmental Phonology
Chomsky & Halle (1968), along with their predecessors, postulated that each
sound segment could be decomposed into a feature matrix or column which essentially
listed each feature with the plus or minus value defining that segment (see figure 1).
The difficulty with this view is that there is no internal organization to these columns.
7
As a result, no distinction can be made between features that are distinctive—that is,
those features that are necessary to distinguish that segment from the other
phonemes in the language—and those that are redundant. In the feature specification
for IxJ in figure 1, the features [high], [back], and [low], traditionally needed to
characterize the vowels, are unnecessary because of the specification of
[+consonantal] as well as [+coronal]. A second difficulty presented by the SPE
model is that feature matrices are unable to capture traditionally recognized groupings
of features. Because segments are represented by a feature column that has no
internal organization, the co-occurrence of features must be considered as coincidental
or arbitrary. There is nothing inherent in the feature specification of hi, for example,
that captures the generalization that all [+back] vowels in English are necessarily
[+round].
As exemplified in figure 1, Chomsky & Halle (1968) claimed that any utterance
could be divided into discrete slices of features where each slice represented one
segment. Researchers who were attempting to extend the claims of SPE beyond
English found that this absolute slicing hypothesis could not adequately account for
N hi -son +son +cons -cons -syll +syll +cor -cor +ant -ant -high -high -low -low -back +back -cont +cont -round +round -nas -nas -lat -lat etc. etc.
Figure 1: An example of feature columns for the word toe based on Chomsky & Halle (1968).
8
suprasegmental phenomena such as tone. Specifically, Leben (1973) observed that in
some instances a segment is deleted, but its tone remains behind and attaches to an
adjacent segment. In addition, he found that some languages have morphemes that
have no segmental value and are represented only by tone. A combination of a high
tone followed by a low one, for example, could change an adjective to an adverb in
some hypothetical language. Leben (1973) also noted that some languages
demonstrate only a small inventory of tone combinations which reoccur on words of
different syllable length. Finally, he observed that single segments, usually vowels,
are able to carry contour tones (which are commonly analyzed as combinations of level
tones). Observations such as these indicated that tones operate independently of,
and are more stable than, segments.
The discovery that tones could operate independently of segments led to the
hypothesis that these components of phonology occupy independent levels of the
representation. Nonlinear phonology commonly refers to these levels as "tiers" and
accounts for the interaction of tiers using association lines. Leben's observations
indicated that the association of the "tonal tier" to the "segmental tier" is not
necessarily one-to-one. Mapping relationships can be many-to-one, as with contour
tones where more than one tone maps onto a single segment, or the relationship may
be one-to-many, in which a single tone maps onto several segments.
The idea that tone needed to be represented independently because its domain
did not match that of the segment led researchers to consider the possibility that other
features may also function independently of the segmental tier. Clements (1976b), for
example, postulating that all features are represented on separate tiers, extended the
hypotheses of autosegmental theory to vowel harmony. According to his view, it is
unnecessary to specify each vowel of a word for the harmonic features. Instead, only
one specification is needed which spreads to the vowel slots over the domain of the
entire word. Following Clements' (1976) lead, several other researchers found that
9
they were able to account for phonological phenomena in a simple and constrained way
if features were extracted out of the matrix and allowed to function independently of
the segment. The term "autosegment" stems from the idea, then, that features and
tones operate independently of the segment in a phonological rule, and in this sense
must be considered to be segments on their own.
The conclusion that a feature column or matrix representation of the segment
was inadequate led researchers to query just what sort of phonological representation
would be adequate. It was noted that hierarchical organizations are common in
linguistics. In syntax, for example, hierarchical phrase structure trees allow groups of
words to function as a unit in syntactic transformations. In a similar fashion, various
features can be naturally divided into groups and a hierarchical arrangement may also
be applied. It should be noted that the evidence for dividing features into groups
comes not from any articulatory or acoustic similarity, but from the common functioning
of features in rule systems (McCarthy, 1988). Many languages, for example, have a
rule which assimilates the place of articulation of a nasal to that of the following
obstruent (as in English bank [baerjk], bent [bent], and bump [bAmp]). Segmental
phonology (following the SPE model) would represent such a rule as in figure 2.
[+nas] -> a cor / _ a cor P ant [3 ant Y back Y back
Figure 2: SPE characterization of a nasal assimilation rule
As illustrated, the linear framework must call on three features, [coronal], [anterior]
and [back], as well as use variables, to indicate that the nasal simply matches the
obstruent's place of articulation. A hierarchical arrangement of features, however, has
the [coronal], [anterior] and [back] features dominated by a PLACE node. The
10
Nasal Obstruent i 0 PLACE node
Figure 3: Nonlinear representation of the Place Assimilation Rule
nonlinear representation of the nasal assimilation rule then, simply requires the
PLACE node of the obstruent to "spread" to the PLACE node of the preceding nasal
as in figure 3. Figure 4 illustrates how the Place Assimilation Rule would apply in a
word such as bank. The fact that nonlinear phonology uses slightly different features
from those of Chomsky and Halle is unimportant here. What should be noted is that
the nonlinear rule refers to only one piece of information, the place of the obstruent,
while the linear rule must call on three features.
Figure 4: Example of the spreading of the PLACE of /k/ to the preceding nasal consonant.
a back / _ a cor (3 cor (3 ant y ant y back
[+nasal]
Figure 5: Example of a possible rule according to linear phonology which is impossible under nonlinear phonology (as described in McCarthy, 1988).
A second advantage presented by the nonlinear representation is that the features
which refer to place of articulation are all grouped under a place node, making the
spread of that node a logical occurrence. As previously stated, a linear framework
11
cannot account for such relationships or groupings of features. Thus a rule such as the
one presented in figure 5 is just as possible as that of figure 2, but is impossible
according to nonlinear phonology.
Phonologists have traditionally recognized four groups of features:
a) the major class features [sonorant], [consonantal], [syllabic]
b) the place features [coronal], [anterior]
c) the tongue-body features [high], [low], [back]
d) the manner features
[continuant], [nasal], [lateral] (SPE, 1968)3
Several researchers have designed feature hierarchies which capture these four
groupings of features (Clements, 1985, 1989; Sagey, 1986; McCarthy, 1988). The
differences among the various proposals stem from the respective authors' hypotheses
about how the features function in language rules. It is generally agreed, for example,
that a MANNER node never operates in a language rule—that is, the features
[continuant], [nasal] and [lateral] never function as a class of segments—and
therefore, is unnecessary in the hierarchy.
The Feature Geometry
The particular feature hierarchy adopted in this paper was initially proposed by
Sagey (1986), and subsequently refined by McCarthy (1988) (see figure 6). The
feature hierarchy depicted in figure 6 can be divided into class nodes and terminal or
3 SPE treats the listed features as maximally binary. See discussion under Underspecification for a description of the nonlinear "privative" and "binary" treatment of features.
12
SKELETAL TIER
[anterior] [distributed]
Figure 6: Adaptation of Sagey's (1986) feature geometry incorporating McCarthy's (1988) refinements and Clements'(1985) schematic representation.
feature nodes. The nonterminal class nodes express claims about how features group
together in phonological rules. The highest of these class nodes is the ROOT node,
which is the structural representation of the segment itself. "Delinking" a ROOT node
implies that that segment is deleted.
The features or terminal nodes [consonantal], [sonorant], [continuant] and
[nasal] attach directly to the ROOT node. As previously noted, phonologists agree
that postulating a MANNER node to dominate [nasal] and [continuant] is artificial
because these features do not function as a class of "manner" features in any attested
language rule. It is hypothesized that the best representation attaches these features
directly to the ROOT node because they group together with all of the place features
to create segments and must, therefore, appear higher than the PLACE node..
13
McCarthy (1988) points out that the major class features, [consonantal] and
[sonorant], function differently from [nasal] and [continuant] in that they delete,
assimilate or dissimilate only when the entire segment is affected or, stated
differently, when the rule makes reference to the ROOT node. As a consequence of
this observation, McCarthy (1988) argues that [consonantal] and [sonorant] should
literally form the ROOT node so that they can be distinguished from those features
which operate in phonological rules. I would agree with McCarthy (1988) that the
major class features function differently than the manner features but have chosen to
depict them as sister nodes (following Sagey, 1986) for ease of representation.
The two class nodes dominated by the ROOT tier are the LARYNGEAL node
and the PLACE node. The LARYNGEAL node dominates the features that
characterize the states of the glottis. Certain researchers (McCarthy, 1988;
Clements, 1985; Sagey, 1986) propose the terminal nodes [slack folds] and [stiff
folds] instead of [voice], as shown here, in order to account for breathy and
laryngealized segments, which occur in some languages. The feature [voice],
however, is the only terminal node required under LARYNGEAL to account for
English data. The node [+spread glottis] is not necessary because voiceless
segments are unspecified for laryngeal status (see Underspecification in this chapter
for further explanation). Glottal stops do not function phonemically in English,
meaning that [+constricted glottis] is not required in the representation.
The class node PLACE does not directly dominate feature nodes, but instead
dominates the nonterminal nodes 'labial', 'coronal' and 'dorsal'. It should be noted that
researchers disagree as to how the nodes dominated by PLACE should be defined.
Some (Chomsky & Halle, 1968; Clements, 1985, 1989; Archangeli & Pulleyblank,
1986) argue that the nodes under PLACE should be defined by their place of
articulation, meaning that PLACE would be expressed by combinations of the features
[coronal] and [anterior]. Sagey (1986) and McCarthy (1985) define the nodes under
14
PLACE according to the active articulator producing the constriction in the vocal tract.
Segments produced using the lips are characterized as labial', those produced with the
tongue blade or tip as 'coronal', and those made by the tongue body are termed 'dorsal'.
Both points of view agree that 'coronal' needs to be further specified in order to
account for the various segments produced with the front of the tongue; Sagey (1986)
and McCarthy (1988) propose the features [distributed] and [anterior].4
[Distributed] separates the "crown" of the tongue into two parts: the blade is
characterized by [+distributed] while the tip is [-distributed]. Similarly, the feature
[anterior] provides a finer definition of coronal according to where the constriction is
made on the passive articulator: palato-alveolar segments are [-anterior] and dentals
are [+anterior]. It should be noted here, that there is considerable controversy
regarding the characterization of English affricate segments which are [-anterior] as
well as a combination of [-continuous] and [+continuous]. Bernhardt (1990),
proposes the mnemonic 'complex' in order to characterize the branching structure of
the [continuant] feature. Bernhardt's (1990) formulation will be followed in this
paper.
The features dominated by the dorsal and labial nodes are primarily needed to
characterize the vowels in English. Clements (1989) argues that vowels and
consonants should have different feature specifications. He proposes that the PLACE
node should bifurcate into CONSONANT-PLACE and VOWEL-PLACE nodes.
Although I would agree that the features [high], [low], [back] and [round] primarily
refer to vowel specifications, the interaction of consonantal and vowel features,
especially apparent during the acquisition process, supports the representation
4 Keating (1990) defines several more 'coronal' places of articulation which are required to describe cross-linguistic data. The features [distributed] and [anterior], however, are the only 'coronal' features required to describe English data.
15
provided by Sagey (1986). Using different features to specify vowels from those used
to specify consonants, as Clements (1989) suggests, would not allow for this
interaction.
Following this definition of the feature hierarchy, it should be obvious that the
nonlinear view has not adopted the strictly binary view of features postulated in the
SPE framework. Although the terminal feature nodes may carry either a plus or minus
value ([-anterior] for example, is needed to account for the alveo-palatals in English),
the higher nodes are held to be privative in the sense that they are either present or
not present in a representation; [-coronal], for example, is not a possibility according
to the view of nonlinear phonology adopted in this paper.
Markedness
Inherent in the feature geometry described above is the notion of markedness
first posited by the Prague School phonologists. Hyman (1975) outlines four currently
accepted definitions of the term "marked." One view refers to the complexity of
segments, denoting those sounds which add features to their specification as marked.
In this sense, Pol is considered more marked than /p/ because it carries the additional
feature of [+voice]. The second possible definition considers unmarked segments to
be those which occur frequently cross-linguistically. According to this view, the
vowels IM and /u/ are unmarked, while /u/ and /tq/ are the marked members of the high
front/high back opposition because they are less commonly attested in phonological
inventories. A third definition incorporates the Prague School notion of neutrality,
which stipulates that the unmarked member of an opposition is the one that surfaces
phonetically when two phonemes neutralize in a given position (Trubetskoy, 1939).
Because both voiced and voiceless obstruents surface as voiceless in word-final
position in German, for example, the voiceless member is considered unmarked. The
final view of markedness, outlined by Hyman (1975), stipulates the unmarked member
16
as being the "productive" or "regular" member of an opposition (p. 146). Hyman
points out that the regular stress pattern for disyllabic nouns in English is for stress to
fall on the first syllable. A noun such as cement, which carries stress on the second
syllable, is therefore denoted as marked according to this view.
The nonlinear view of markedness embodies all four definitions outlined above.
Originally, markedness was a language-specific notion whose definition was based on
the phonological rules operating within that language. Current phonological theories,
however, place heavy emphasis on cross-linguistic phenomena, stipulating that
universally attested phonemes are unmarked and form part of an innate Universal
Grammar. According to this view unmarked sounds are acquired earlier than marked
ones because the marked values represent more unusual options which require
positive evidence from the linguistic environment.
The feature hierarchy incorporates the notion of markedness in two ways.
First, unmarked segments are those whose salient or most characteristic feature is at
a higher level in the hierarchy. Thus, /s/ is less marked than III because it does not
require the more deeply embedded feature [-anterior] as part of its specification.
Second, the feature hierarchy encodes markedness in terms of complexity of the
feature specification. In this view, /s/ is considered more marked than III because it
requires the added feature tier [+continuant]. As pointed out by Bernhardt (1990),
the concept of markedness is inherently hierarchical because one feature value is
usually viewed as being more likely than the opposite value.
Underspecification
As previously outlined, markedness values distinguish universal properties
from language-specific properties. Since the most desirable representation is also the
simplest one, it has been postulated that it is not necessary to include any universal
properties in a phonological representation because these properties are predictable
17
from Universal Grammar. Researchers hypothesize that universal 'redundancy rules'
fill in missing features at the surface level of representation (Archangeli, 1984).
Archangeli (1984) points out that it is desirable to further simplify the model by
removing all predictable distinctive features from the phonological representation
which then results in "underspecified" segments.5
Currently there are two accepted models of underspecification. 'Contrastive
underspecification' (Clements, 1987; Christdas, 1988) requires that only those
features required to distinguish a phoneme in a given context need to be specified in
underlying representations. Acquisition of this system requires that the child discover
the features which function contrastively in the language of her environment. The
second view, 'radical underspecification' (Kiparsky, 1982; Archangeli, 1984;
Pulleyblank, 1986b), includes only unpredictable values for features in the underlying
representation. In this view, not only the universally predicted features are extracted
from the feature specification, but also those features generated by language-specific
rules. When acquiring a radically underspecified phonological system, the child's first
attempts at a sound will agree with the feature specification provided by Universal
Grammar. If a language utilizes a more marked option in predictable contexts, then its
feature specification will be filled in by a language-specific redundancy rule. If the
more marked feature value is used contrastively in the language it becomes part of the
underlying representation.
5 The initial proposals of SPE did not include the notion of underspecification. However, Chomsky and Halle introduce a form of underspecification in the final chapter of SPE. They propose that universal markedness rules, or redundancy rules, apply to the underlying representation of an utterance before any language specific phonological rules apply. According to this formulation, then, language specific phonological rules act on a fully specified underlying representation. The current view of underspecification holds that redundancy rules apply as late as possible in the derivation.
18
Radical underspecification is the view which has been adopted in this paper. A
maximally underspecified model is regarded as advantageous because it requires less
information to be stored by the language learner and allows language properties to be
derived using rules. The contrastive underspecification model places an undesirable
emphasis on the storage of phonological representations.6 The second advantage of
radical underspecification is that it incorporates the notion of markedness, in that
redundancy rules can be considered as statements defining the unmarked values of
features. A universal rule such as [+sonorant] -> [+voice] interprets [+voice] as the
unmarked value for [voice] on sonorants.
It is noted that certain segments appear to be "transparent"; that is, they do
not interfere or block the occurrence of some phonological rules, despite the fact that
their feature specifications match the input requirements of these rules. This
transparency effect is accounted for by postulating that these segments are not
specified for those features involved in the phonological rule. Magnusson (1983), for
example, reports that assimilation to labial and velar places of articulation was more
frequently attested than alveolar assimilations in her child language data. This
observation is accounted for in nonlinear phonology by stipulating that coronal
(alveolar) segments are unspecified for place features and are therefore more
vulnerable to the spread of dorsal and labial features once these are specified, or
6 It should be noted that some theories of phonological acquisition emphasize the storage of lexical items before the morphological or phonological segment-level analysis takes place (e.g. Macken, 1979; Ferguson & Farwell, 1975). The current author's view holds that while phrases or lexical items may initially be acquired as unanalyzed units, as soon as sufficient input is provided by the environment, the child replaces these with minimal representations allowing redundancy rules to compute the surface realization. This view is in conflict with Ferguson & Farwell (1975) who "assume the primacy of lexical learning in phonological development" and argue that phonetic words continue to be stored over the life span (p. 437). However, it is consistent with generative grammar accounts of syntax acquisition (e.g. Chomsky, 1964).
19
marked, in a child's system. If these features are not yet marked (acquired), the
"default" redundancy rule inserts the coronal specification, as is commonly noted when
children "front" velar segments (e.g. dog is produced as [dad]). The minimal
specifications of the English consonants are presented in Appendix 1.
Prosodic Phonology
In addition to developing more precise feature representations, current
research is devoting much time to the development of theories that account for how
segments combine to form higher level prosodic units. The only hierarchical structure
imposed by SPE on a row of segments was that required by English syntax. That is,
SPE assumed that the morpheme was the basic unit into which phonemes were
grouped. Morphemes then combined to form words, which could be strung together to
make phrases and sentences. Researchers pointed out, however, that syntactic
bracketing of this nature was inadequate to account for the placement of stress in
languages. In addition, the morphological level of representation provided no
indication of which sequences of phonemes are considered well-formed in a particular
language. Both of these shortcomings could be overcome by referring to the syllable
as being intermediate between the segmental and the morphological levels of
representation.
Hyman (1985) outlines two basic arguments supporting the existence of the
syllable. First, stress is assigned to a syllable rather than to a phoneme or a word.
This claim is demonstrated by the fact that certain syllable shapes attract stress more
readily than others in a particular language (see below for more detailed discussion).
Second, by making reference to the syllable, it is possible to account for how segments
group into well-formed constituents. Languages only allow certain consonants or
combinations of consonants in the syllable onset position, for example. Van der Hulst
& Smith (1985) assert that accounting for these two points—stress placement and
20
providing a definition of the notion of well-formed syllable—are the requirements of a
satisfactory syllable theory.
The reality of the syllable as the basic unit grouping segments into higher order
however, with regard to the internal structure of the syllable. Although several
theories have been proposed by different researchers based on their observations of
various languages, these theories may be divided into two basic types: those which
support the traditional view of dividing syllables into 'onset' and 'rhyme' constituents,
and those which divide the syllable into 'weight units' or 'morae'.
The traditional onset-rime syllable theory was first introduced by Pike & Pike
(1947) and is currently supported in works such as Halle & Vergnaud (1980), Kaye,
Lowenstamm & Vergnaud (1987), and Steriade (1988). According to this theory the
most basic opposition within the syllable hierarchy is that of onset versus rime (see
figure 7 below). The onset directly dominates a syllable-initial consonant or
consonants, as with clusters. The rime further branches to a nucleus, usually
dominating a single vowel or two vowels in the case of diphthongs, and a coda or
margin constituent, which dominates the remaining consonants of the syllable.
According to onset-rime theory, the basic syllable shape is CV, as would be
indicated by the first level of branching. Complexity is increased by adding more
constituents is readily accepted by phonologists. Considerable controversy exists,
Onset Rime
Nucleus Coda
C C V V C C
Figure 7: The hierarchical arrangement of the syllable as proposed by onset-rime theory (based on Pike & Pike, 1947).
21
deeply embedded constituents to the syllable shape. The next stage of complexity,
therefore, would entail branching within either the onset or rime nodes as the shapes
C C V (branching onset) or C V C (branching rime) require. A shape such as C V V is
considered to be even more complex because it requires branching at the even finer
nucleus level of representation.
Figure 7 illustrates that the rime node dominates the nucleus and coda
constituents. This configuration indicates that these sister nodes often operate
together in phonological rules. Two observations illustrate this fact. First, it has been
observed in many languages that when the vowel under the nucleus node is deleted,
the coda constituent, and never the onset, is resyllabified under the nucleus node. The
English word b u t t o n [ b A t s n ] when p r o n o u n c e d rapidly becomes [ b A t n ] in which the /n/,
originally dominated by the coda, fills the nucleus position. The second observation
supporting the sister relationship of the nucleus and coda within the rime was first
pointed out by Jakobson (1931, 1937) and Trubetskoy (1939). These phonologists
noticed that the assignment of stress is often sensitive to the structure within the
rime. Specifically, they observed that "heavy" syllables—that is, closed syllables or
those with long vowels —attract stress, while open or "light" syllables with short
vowels do not. This generalization is captured by the statement that stress is
assigned to syllables with branching rhymes (where branching can occur either at the
level of the rime or within the nucleus). It should be noted that the status of the onset
is irrelevant when assigning stress.
As previously noted, van der Hulst & Smith (1985) state that a satisfactory
syllable theory should account for the assignment of stress in a particular language. In
order for onset-rime theory to fulfill this requirement, the formal representation must
indicate that only the rime distinguishes between heavy and light syllables and that
onsets are "weightless." Hyman (1984) argues that resorting to the geometry of the
rime, as onset-rime theory does, is not sufficient for determining syllable weight. He
22
points out that some languages only regard syllables with long vowels (branching
nucleus) as heavy but treat closed syllables (branching rime) as light. Still other
languages, though counting CVC syllables as heavy, treat CV? sequences as light
despite the fact that a glottal stop appears to be filling the coda position. Thus, it is
sometimes necessary to look below the syllable hierarchy to the feature content in
order to determine phonological weight. In addition, Hyman points out that there is
nothing in the formal representation of onset-rime theory which indicates that the
syllable onset is weightless and thus plays no role in stress assignment. In order to
capture the generalizations regarding stress placement, individual languages must add
definitional statements to the syllabic representation, a move which adds a
considerable burden to the learnability of the system.
Recently, phonologists such as Hyman (1984), McCarthy & Prince (1986), and
Hayes (1989) have proposed that generalizations regarding syllable structure are
better captured using 'weight units' or 'morae' rather than an onset-rime hierarchy.
These morae constitute a weight tier which is intermediate in the hierarchy between
the segmental feature geometry and the syllable tier. According to Hyman (1985),
each mora "defines a beat or peak of sonority" within the syllable (p. 20). Supporters
of the weight unit theory of syllabification agree that the moraic structure of languages
can vary. Essentially languages differ in the rules required for assigning moraic
structure depending on how that language distinguishes heavy syllables from light
ones, as discussed above. Recall that some languages regard CVV and CVC
syllables as heavy while only CV shapes are light. Other languages, however, only
consider CVV syllables as heavy and hold that both CVC and CV syllables are light.
Once this heavy/light syllable distinction has been established for a certain language,
morae may be assigned: light syllables contain only one mora and heavy syllables
contain two. In this sense, morae reflect the weight of a syllable.
23
Figure 8: The internal constituent structure of the syllable as proposed by moraic theory (elements in parentheses are optional).
According to moraic theory, syllable-initial consonants attach directly and
individually to the syllable node. This view, therefore, unlike the traditional syllable
theory, does not maintain any opposition between the onset and the rest of the
syllable (see figure 8). Controversy exists over the representation of post-vocalic
(coda) consonants. Some researchers (Hyman, 1984; Hayes, 1989) claim that
syllable-final consonants should be linked to the mora of the preceding vowel (or
consonant if the language considers closed syllables to be heavy), while others
(Clements & Keyser, 1983; Kiparsky, 1980) argue that they should, like onsets,
attach to the syllable node. The position adopted in this paper is that coda consonants
are adjoined to the mora of the preceding consonant (see, however, chapter 5 and
Hayes (1982) for discussion of extrametrical consonants).
Based on observation of many languages, it has been suggested that the
maximum number of morae allowed in a syllable is two (McCarthy & Prince, 1986).
All languages, then, must be either monomoraic, meaning they do not distinguish
between heavy and light syllables (e.g. Japanese), or bimoraic and therefore sensitive
to syllable weight. English falls into the latter bimoraic category and allows any
sonorant (vowel or consonant) to fill the first mora position in the syllable (recall the
button example in which the word final syllabic /n/ moves into the position of the first
mora in the syllable during rapid speech). English allows the second mora position in
the syllable to be filled either by a vowel if the syllable contains a diphthong, or by a
24
Figure 9: Moraic representation of the syllable hierarchy for the word pin.
[+sonorant] consonant (see figure 9). Obstruents may never fill this position in
English.
The basic syllable according to moraic theory is a monomoraic CV syllable
where the vowel is dominated by a mora and the onset consonant is directly attached
to the syllable node. The next level of difficulty would entail establishing a bimoraic
syllable as is required by diphthongs (CVV) and closed syllables (CVC, where the
final consonant is [+sonorant]). Moraic theory disregards onsets in the
establishment of syllable structure; it is difficult to discern, therefore, whether a CCV
syllable (monomoraic) is actually considered to be less complex (and thus easier to
acquire from the child language acquisition point of view) than a CVC (bimoraic)
syllable. Bernhardt (1990) suggests that the development of multi-consonant
sequences could occur at any time, but perhaps could be delayed until the critical
parameters for syllable structure (i.e. bimoraic syllables) have been set.
Contrasting the internal structure of syllables according to both moraic and
onset-rime theory, several empirical differences become obvious. First, the distinction
between heavy and light syllables is more defined in the moraic theory representation;
onset-rime theory must make reference to language-specific rules in order to make this
distinction clear. Second, moraic theory does not place any importance on onset
segments while onset-rime theory maintains the opposition between these syllable-
initial constituents and the rime. According to the onset-rime view, then, consonant
25
clusters in onset position form a unit; the moraic theory provides no representation of
such a unit and simply appends each consonant individually to the syllable node. A
third difference arises from the way each theory treats vowel constituents. Onset-
rime theory places all vowels (short, long and diphthongized vowels) under the
nucleus node. Moraic theory, however, represents long vowels and diphthongs using
two morae which attach individually to the syllable node. In this sense, moraic theory
treats the second vowel of a diphthong as equivalent to a consonant in establishing
heavy syllables. Recall that onset-rime theory considers a CVV syllable to be more
complex than a CVC syllable because the former requires a deeper level of branching
within the nucleus node. Finally, the representation of onset-rime theory presents a
richer hierarchy using branching at each level, while moraic theory utilizes a more
linear representation of the syllable.
Syllables and Segments Combined
1 An outline of possible syllable hierarchies, as well as a feature hierarchy, leads
to the question of how these two levels of phonology may be combined. McCarthy
(1979) originally proposed that a 'skeletal tier', made up of C's and Vs, mediates
between the syllabic and segmental hierarchies. Clements & Keyser (1983) and
Christdas (1988), who currently support the existence of a CV tier, point out that this
tier provides the input to the syllable hierarchy which, in their view, builds not on
segments but on consonant and vowel constituents. According to these phonologists,
the CV tier "can be considered to contain quantitative information about a phonological
string" (Christdas 1988: 23). In other words, the skeletal tier provides a count of the
number of segments making up a syllable unit; such a count is not provided elsewhere
in the phonological derivation. Levin (1985) and Lowenstamm & Kaye (1986)
conclude that the use of Cs and Vs in the skeletal tier is unnecessary because the
consonant/vowel distinction may be distinguished by the higher level syllable
26
structure. These researchers support the onset-rime syllable theory and point out that
vowels are always dominated by nucleus nodes, while consonants fall under onset and
coda nodes. As a result, Levin (1985) and Lowenstamm & Kaye (1986) have
replaced the C and V symbols with a sequence of X's. It should be noted that the
difference between a C V tier and an X tier is minimal; both views provide a measure of
the number of segments present.
Hyman (1984), McCarthy & Prince (forthcoming) and Hayes (1989) support
the view that no skeletal tier is needed to mediate between the syllable and
segmental hierarchies. Hayes (1989) points out that phonological rules have been
observed to count morae and syllables, but no known phonological process exists that
counts segments. Thus, a measure of the number of segments making up a syllable is
not needed. What is required, however, is a measure of syllable weight, and this may
be provided by the moraic theory supported by these phonologists. According to
Hyman (1984), McCarthy & Prince (forthcoming) and Hayes (1989), then, the ROOT
node of the segmental hierarchy is directly dominated by the syllable node, in the case
of onset consonants, or a mora, in the case of all other constituents.
Just which of these views—the C V tier, the X tier or no skeletal tier—best
accounts for child language acquisition data remains unclear. Reports based on the
presence of morphophonemic alternations indicate that some level of mediating tier
may be necessary. A child, for example, who produces [da] for dog and [dagi] for
doggy, and who recognizes the relationship between these two words, appears to
realize that a /g/ is underlyingly present in dog but is simply unable to produce syllable
final consonants (Dinnsen et al., 1980). This realization could be represented by an
empty X-slot-that is, a node with no feature values-if a skeletal tier is present in the
representation. In addition, intuitively it makes sense that phonological rules and
derivations should have access to phoneme-sized units at some level of the
representation.
27
The Acquisition Process
Theories of nonlinear phonology as described above appear to present an
overwhelming task for the language learner. In reality, however, the acquisition
process can be described by making reference to syllable and segmental hierarchies.
Based on the predictions of Universal Grammar, the child comes to the language
learning task with the established basic C V syllable. From this level, two
possibilities for further acquisition exist. The child may either add branches to the
syllable hierarchy, by developing a C V C syllable for example, or may develop the
feature hierarchy and increase the inventory of segments which may fill the C or V slot
of the established C V syllable shape.
Based on her work with phonologically disordered children, Nettelbladt (1983)
generalizes that severely disordered children have undeveloped syllable structure,
whereas children with mild-to-moderate disorders have difficulty at the segmental
level. Bernhardt (1990) suggests that this fact is accounted for if the syllable level of
representation is considered a more basic (meaning "not as embedded" in this case)
level than the segmental level. This suggestion is exemplified by Pollock's (1983)
description of a severely disordered child who was able to increase his segmental
inventory only after the acquisition of closed syllables. It is possible, therefore, that
certain levels of complexity in the syllable hierarchy coincide with levels within the
segmental hierarchy and that these levels must be attained before the feature
hierarchy can continue to develop. Further research is required to substantiate such a
claim.
A concluding remark addresses the nature of the acquisition process described
above. Phonological acquisition, in the view of nonlinear phonology, can be described
as a process of building up the syllable and segmental hierarchies. At no point is the
child viewed as deleting features or segments from a more complex underlying
representation. A syllable shape or segment missing from a child's phonological
28
inventory is, therefore, not considered to be "simplification" of the output. Instead, the
child has not yet acquired certain branches or levels of the hierarchy.
To date very few researchers have attempted applying the recent nonlinear
advances in phonological theory to child language acquisition data or data taken from
the speech-language pathology literature. The first attempt, by Gandour (1981), used
Kahn's (1978) syllabic theory of phonology to present a reanalysis of the data of a
phonologically delayed subject. Following this lead, Spencer (1984) reanalyzed the
data presented in Grunwell & Pletts (1974) using a nonlinear framework for
description. Similarly, Spencer (1986) used nonlinear principles to present a
reanalysis of phonological acquisition data of the typically developing child first
outlined in Smith (1973). More recently, Stemberger (1988) presented nonlinear
analyses of processes operating across word-boundaries in the phonology of his
daughter. All of the cited research show that when phonological acquisition data is
examined from the point of view of nonlinear phonology, the data no longer appears to
be deviant or idiosyncratic, but instead, can be seen to follow the general rules and
principles governing the languages of the world.
If nonlinear phonology provides a superior means of accounting for language
acquisition data, then it should follow that the principles of this theory should have
validity for the remediation of phonological delays. The only research to date which
has focussed on the application of nonlinear principles in the clinical setting is that
recently completed by Bernhardt (1990) and the research findings presented here.
29
CHAPTER 3
METHOD
In order to explore the application of nonlinear phonology in the clinical setting,
a longitudinal intervention study was carried out with a set of identical male twins,
aged 5;7 at the onset of the project. The boys are from a middle-class family where
English is the only language spoken in the home. There are no other siblings in the
family. The twins had had no speech or language therapy prior to that received in the
study. This point is important because it meant that no "biases" from previous
intervention needed to be accounted for or overcome in therapy. Instead, each twin's
phonological inventory at the commencement of the study was one which had evolved
spontaneously.
The methodology and design of this study was adapted from that of Bernhardt
(1990), with a few changes introduced in order to accommodate the twin subjects of
the current project. Bernhardt's study employed both a multiple baseline and an
alternating treatment design. The details of these will be developed below.
Initial Assessment
Standardized language tests were administered at the beginning of the study
by the speech-language pathologist who first identified the twins as possible subjects
for the project. These measures included:
a) The Peabody Picture Vocabulary Test - Revised (Dunn & Dunn, 1981)
30
b) The Expressive One-Word Picture Vocabulary Test (Gardner, 1981)
c) The Structured Photographic Expressive Language Test-II (O'Hara Werner & Dawson Kresheck, 1983)
d) The word discrimination subtest of the Test of Language Development - Primary (Newcomer & Hammill, 1982)
e) The Test of Auditory Comprehension of Language - Revised (Carrow-Woolfolk, 1985)
These tests were readministered by the same examiner at the end of the project and
made up part of the multiple baseline design. Although syntactic and pragmatic goals
were never the focus of therapy sessions, the possibility existed that activities which
emphasized the use of phonological targets in sentences and natural conversation
would also have a positive effect on general language ability. The results of the post-
study language measures are discussed in chapter 6. In addition to the above, the
parents were asked to fill out a detailed case history form, which provided further
information regarding the medical background of each of the twins, as well as the
acquisition of major motor and speech and language milestones.
The initial phonological assessment was recorded on Ampex 631 tapes using a
Nagra IV-D reel-to-reel tape recorder with an A K G D-202 E l microphone. This
assessment was administered to each of the twins by the author of the current study.
The assessment procedure, resembling that of Hodson (1980), involved eliciting
single words using objects and pictures. The word list used in this study, developed
by Bernhardt (1990), included words which assessed the production of "all consonants
in syllable-initial word-initial position, syllable-final word-final position, intervocalic
medial position and, where possible, syllable-final within-word position." In order to
see whether the complexity of the word in which it appeared affected the production of
a consonant, segments were elicited in CV, V C and C . V C . shapes when such words
existed, as well as within clusters and polysyllabic word shapes. Finally, selected
31
nouns with [i] added to the end (e.g. gum -> gummy1), and the present progressive
form (-ing) of several verbs (e.g. run. -> running') were elicited in order to assess
whether morphophonemic alternation had any effect on the production of word-final
consonants (which became word-medial with the addition of the endings). A list of
these words is presented in Appendix 2. The phonological assessment was
supplemented with an oral mechanism examination based on suggestions presented in
Robbins & Klee (1987) and an evaluation of the stimulability for production of those
phonemes not evidenced in the twins' productive inventory.
The recordings of the phonological assessments were transcribed noting any
spontaneous and elicited repetitions, as well as self-corrections. A Revox reel-to-reel
tape recorder and Sennheiser HD 540 headphones were used for this procedure. The
data was then analyzed using the phoneme and cluster realization worksheets and the
phonotactic analysis worksheet of Grunwell's Phonological Assessment of Child
Speech (1985). Based on the results of these analyses, targets for remediation were
chosen. These targets fell within one of two conditions (segmental versus syllabic
condition, see below), to which the twins had been randomly assigned.
Segmental Condition
The main question that remediation within the segmental condition was to
answer was whether the feature geometry of nonlinear phonology can predict which
segments should be targeted first in therapy. As outlined in the previous chapter, the
feature hierarchy predicts that segments which have their "salient" or most
characteristic feature at a higher level in the hierarchy should be more quickly acquired
than segments with lower or more deeply embedded salient features. As a result, two
segments—one representing a higher level, and one representing a lower level target
of the feature hierarchy—were chosen as goals for the first block of therapy. Alternate
training of two segments not only allowed us to test the predictive power of nonlinear
32
phonology, but it also allowed for intensive training of one segment followed by a
period where the child could concentrate on that speech sound and generalize it to
conversation on his own, while therapy continued with the second target. Such a
cyclic approach was first introduced by Hodson & Paden (1983).
Therapy did not involve targeting all segments within a sound class. It was
assumed, and hoped, that the acquisition of one segment would generalize to
segments with similar feature geometries serving as baseline measures. The
acquisition of /z/, for example, was expected to generalize to the production of /s/,
since the two segments differ only by the laryngeal feature [voice]. It should be noted
that the traditional notion of sound class—that is, segments which function similarly in
a language rule—is captured in nonlinear phonology in terms of similarity of feature
geometry. Words used in therapy activities did not include any of the test items of the
major and minor probes (see below). In addition, training words consisted only of
syllable shapes already present in the twins' productive inventory. All segments
other than the target segments of these words were also present in the twins'
production repertoire. Therapy focussed on the acquisition of the target in all word
positions.
Syllabic Condition
The second twin was assigned to the syllabic condition, which focussed on
establishing new syllable shapes in the productive inventory. For the twins this
entailed targeting word-initial consonant clusters. All clusters targeted were made up
of segments the twins were producing consistently in at least one word position. As
with sound classes in the segmental condition, not all clusters were targeted in
therapy. Some served as baseline measures and remained untrained to see if
generalization from targeted clusters would occur.
33
As described in the preceding chapter, there is considerable controversy over
how the syllable hierarchy should best be represented. The main purpose of training
within the syllabic condition, then, was to see which approach resulted in faster
acquisition of therapy goals, either an approach reflecting the moraic theory or one
reflecting the onset-rime theory. Recall that faster acquisition time is thought to occur
because the syllabic theory used in training more closely resembles the way in which
the mind organizes the syllable. A second test for the "correctness" of this theory is
the amount of generalization that occurs across untrained clusters. Details regarding
the training differences between these approaches and the results will be discussed in
chapter 5.
An alternating treatment design was also used in the syllabic condition. The
difference here, however, is that the goals of each condition were of equal difficulty so
that the difference in acquisition time could only be attributed to the training approach.
In the segmental condition, it was hypothesized that the two segments were of
unequal difficulty because of their respective feature geometries, and that acquisition
time would reflect this difference. Consonant clusters were considered to be of equal
difficulty if their differing segment reflected similar features. With s-clusters, for
example, /sn/ could be trained under one theory and compared with /si/ trained under
the opposite theory. In this case the features of /n/ and l\J are considered to be similar
and, therefore, cluster acquisition should reflect equal difficulty. It was not always
possible, however, to keep both conditions exactly the same; thus it was occasionally
necessary to resort to balancing an easier and a more difficult cluster against two
clusters of medium difficulty (see chapter 5 for details).
Therapy Schedule
The twins in this study were seen three times per week for individual therapy
sessions which lasted thirty to forty-five minutes each. Twice a week therapy took
34
place at their elementary school, and once each week they were seen at their daycare
centre. The twins alternated being the first to receive therapy.
The intervention programme was divided into three blocks of therapy, and each
block was divided into two cycles (see figure 10 below). Half of the cycle (three and
one half sessions) was spent targeting one feature or training clusters using one
syllabic approach, while the second half of the cycle (another three and one half
sessions) targeted the second feature or syllabic approach. A review of the cycle's
targets took place on the eighth session. The ninth and final session of the cycle was
a "minor probe" which assessed the acquisition progress of treatment targets by
eliciting them in single words not trained in therapy (as before, pictures and objects
were used).
Treatment Block (19 sessions)
Two cycles (9 sessions each) session 1
session 2
session 3
session 4
session 5
session 6
session 7
session 8 review of all goals of cycle
session 9 minor probe
one week vacation from therapy i
Major Probe (the 19th session of the block)
therapy targeting segment 1 (higher feature in hierarchy) or word-initial clusters using moraic approach
— therapy targeting segment 2 (lower feature in hierarchy) or word-initial clusters using onset-rime approach
Figure 10: Summary of the design of one therapy block
35
The production of therapy targets in connected speech was assessed by having
the twins retell stories in which the target segment occurred frequently (Clinical
Probes of Articulation Consistency [Secord,1981] stories were used for segmental
goals, while cluster goals were targeted using stories created by Bernhardt).
Because retelling the stories proved to be a difficult task for the twins (their auditory
recall was below age level), this procedure often resorted to conversations about the
accompanying pictures. This change allowed the targets to be produced in a natural
way and provided reliable results. Where generalization to specific segments or
clusters was expected, these were also tested using the same single-word elicitation
and connected speech procedures.
The third purpose of the current study was to assess the possibility of one twin
influencing the other's learning without direct training from the speech-language
pathologist. That is, would one twin acquire the other's targets simply because of the
amount of time they spend playing and conversing with each other? In order to
evaluate whether any "cross-talk" was occurring, the minor probe for each twin
included the targets of both the segmental and the syllabic conditions.
If the minor probe results indicated that a target segment or cluster had been
acquired and generalized to conversational usage, then new targets within the same
condition were chosen as goals for the second cycle of the block. If there was no
evidence of acquisition, then the cycle was repeated using different activities to
maintain interest. The second minor probe was followed by a week's vacation whose
purpose was to ensure that the major probe, administered immediately after, reflected
the spontaneous productive inventory of each twin. The major probe was a repetition
of the phonological assessment administered at the beginning of the project.
The first two blocks of therapy targeted goals within the conditions to which
each twin had been assigned. After the first block an environmental reinforcement
programme was initiated. This addition consisted of the twins' daycare workers
36
providing verbal reinforcement for correct spontaneous productions of therapy targets.
At the same time each twin was awarded a check mark which could be turned in to the
examiner for a prize once a certain number of checks had been earned. Goals for the
third block of therapy were chosen based on gaps in the twins' phonemic inventories.
In most cases this meant training targets from the opposite twin. The parents became
involved in the study at this point by playing games and completing therapy activities
with the twins at home. The involvement of the parents had not been sought before
this time in order not to confound any natural cross-talk that might occur between the
twins.
Therapy Procedure
The design of individual therapy sessions was relatively consistent throughout
the project and followed the order:
1) Auditory awareness training consisted of reading stories and poems or
singing action songs and poems that focussed the child on the segment or cluster goal
of the session. This activity was usually done under amplification.
2) Auditory discrimination training contrasted the target segment and the
twin's production using minimal pairs.
3) A series of production tasks whose level of difficulty depended on the twin's
production ability followed the auditory tasks. Initially, these activities focussed on
imitation in a game or role-play situation, but moved on to production in short phrases
and sentences in conversation as quickly as possible. All treatment sessions were
recorded on Fuji C r 0 2 (FR-II) tapes using a Marantz PMD 220 cassette recorder and
an A K G SA 41/1 microphone.
The data reported in the following chapters is drawn from the single-word
elicitation tasks of the minor and major probes, from the story-retell conversations of
the minor probe and, where specified, from the production data of individual treatment
37
sessions. Language samples were recorded at the time of each of the major probes.
In addition, connected speech occurred (and was encouraged) during minor probes and
therapy sessions. Where conversational use of segments differed from single-word
use, it will be specified. In general however, it was found that the probes, especially
the major probes, accurately reflected the subjects' spontaneous use of all segments.
38
CHAPTER 4
T H E S E G M E N T A L CONDITION
When speech-language pathologists are faced with assessing a phonologically
delayed child, they typically begin by administering an assessment tool, usually
requiring the child to label pictures or objects, in order to determine appropriate
intervention goals. As previously noted, the bases for choosing one sound or process
for remediation over another are relatively ad hoc and depend on suggestions such as
following the sequence of acquisition of typical children or remediating those sounds
which would gain the child the most communicative success. Utilizing a nonlinear
framework to determine intervention goals requires the clinician to first assess the
productive phoneme inventory of the child. This inventory is then analyzed according
to the minimal specifications of each phoneme outlined in Appendix 1, and the child's
established feature hierarchy is determined. From here, undeveloped nodes and
branches can be outlined and decisions regarding remediation are made.
Adopting a nonlinear framework for determining the segmental targets for
remediation in the current phonological intervention project led to the analysis of three
questions. First, does the feature geometry lead to the accurate prediction of
treatment targets? Recall that segments having their most salient feature at a higher
level in the hierarchy are predicted to be acquired more quickly than segments with
lower or more deeply embedded salient features. The second question investigated
whether establishing a feature required for the acquisition of one segment would
generalize to the spontaneous acquisition of targets requiring the same feature.
Would the acquisition of [+continuant] for /f/, for example, generalize to the acquisition
39
of hi or Isl, which also require [+continuant] to be established? Spontaneous
generalization of this nature would provide independent evidence in favor of targeting
one level of features over another. Finally, the third question resulted from using
twins as subjects for this study. Specifically, it was asked whether the twin placed on
the syllabic condition would acquire the segmental targets without any direct
intervention. The spontaneous acquisition of one target before another would provide
further evidence in favor of targeting higher versus lower features. Before dealing with
the responses to these three questions in detail, the segmental inventory of the twins
at the commencement of the project will be described.
The Starting Point
Initial goals for treatment were determined based on the analysis of the data
elicited at the first grand probe. The transcribed single-word data is presented in
Appendix 3. At the outset of the study the twins had moderately-severe phonological
delays. Based on parent report and observation of them playing together, the twins
were completely intelligible to each other. The parents reported that they could
understand the twins 100% of the time, but they estimated that strangers could
comprehend them only 75% of the time. This latter estimate was somewhat generous.
The twins entered the study with identical phonetic inventories. Because they
were not discriminating between their production and the adult target form, these also
represent their phonological inventories. The twins provided identical productions for
almost all target words, with only one significant exception which will be addressed in
the next chapter. It is worth mentioning that none of the twins' surface realizations of
adult targets was unusual; all substitutions are commonly cited in the phonological
acquisition and disorders literature. Since neither of the twins had difficulty producing
the vowels of English, these sounds are ignored in the present study and only
consonantal data is analyzed. The consonantal segment inventory for word-initial,
40
p t k
b d g
m n
w j
Figure 11: Word-initial phonetic inventory of both subjects of this study.
p t k
b d g
m n
s
w r j
Figure 12: The syllable-initial-within-word phonetic inventory for both subjects of this study.
p t k
b d g
m n n
s
<1> r
Figure 13: The word-final phonetic inventory for both subjects of this study.
syllable-initial-within-word, and word-final positions are outlined in figures 11, 12 and
13. The segment [1] in figure 13 is entered in angle brackets because of its marginal
status for both the twins. The status of HI was difficult to discern in word-final
position from the recordings; for both of the subjects it was judged to be an [1] rather
41
than a vowel only 50% of the time. The rest of the segments were well established for
each twin.
In descriptive terms it can be seen that the twins had not yet established
fricatives, affricates, liquids and what shall be described here as a laryngeal fricative
(/h/) in their word-initial inventory. The syllable-initial-within- word and word-final
inventories showed essentially the same productive segments as for word-initial
position, with the addition of the liquid [r] and the fricative [s]. This latter segment
was very productive since voicing distinctions were not being marked in the fricative
class (i.e. fricatives all surfaced as [s] in medial and final position regardless of the
laryngeal status of the adult target). It should be noted that the twins were
attempting to mark the [-continuant] [+continuant] status of affricates. In word-initial
position these segments surfaced primarily as [t] and [d], but in medial and final word
positions they were more consistently produced as [ts] and [ds]. Finally, note should
be made of the subjects' 'default' segment, [j], which was produced for both / l / and /h/
in initial and medial word position. The term 'default' is used here to refer to a robust
segment which the language learner substitutes for complex unestablished segments.
When the nonlinear minimal specifications of each of the productive segments
are combined, the established feature hierarchy of the twins is determined (see figure
14). In figure 14, the terminal node [+voice] is required under the L A R Y N G E A L
class node to characterize the voiced obstruents. The 'labial' node accounts for the
bilabial stops and nasal, while the [+round] terminal feature is required in the
specification of the glide, /w/. The 'dorsal' node is the salient feature of the velar
consonant specifications and [+nasal] is the same for the nasal consonants. The
[consonantal] feature is required for the specification of all consonants.
42
SKELETAL TIER
ROOT NODE
LARYNGEAL NODE
[+voice]
[consonantal] [sonorant]
x[+nasal] [+continuant]*
labial
PLACE NODE
coronal dorsal
[+round]
Figure 14: The established feature hierarchy at the beginning of intervention for both subjects. (* The 'complex' aspect of affricates was partially established.)
The status of the glides, Av/ and /j/, with respect to the feature [consonantal] is
uncertain. The position adopted here is in agreement with Hyman (1985) who argues
that glides are really vowels filling consonantal slots (p.77). This position is reflected
by the lack of [consonantal] in the minimal feature specification and the marking
[sonorant] which is required in the characterization of all vowels, glides and liquids.
The segments /w/ and /j/ remain unmarked for the [consonantal] feature because this
status is redundant by the position these segments occupy in the syllable.
Since 1)1 is not marked for [consonantal], its minimal specification consists
solely of [sonorant] which is also the minimal specification of the neutral shwa vowel
in English.7 Sharing this representation should not confuse the language learner or
7 Elsewhere it has been argued that [-anterior] under the 'coronal' place node is required in the minimal specification of / j / and that /w/ is the most underspecified of the glides (Shaw, personal communication; Bernhardt, 1990). Based on the fact that /j / surfaced as the twins' default segment, it is argued here that /j/ should be the least specified of the glides. It should be noted that [-anterior] is not required to differentiate / j / from other English segments provided that the default 'coronal' place node is supplied by redundancy rules.
43
the application of phonological rules, because the position the segment occupies in the
syllable defines whether it surfaces as shwa or /j/. In other words, syllable onsets,
which must be filled by consonants, will surface as /j/, while syllable nuclei or slots
dominated by morae (depending on the preferred theory) will always be realized as
shwa. This account of 1)1 provides a neat analysis of the twins' favorite segment.
Essentially, the twins' underlying representation of l\J and fhj in syllable-initial position
(both word initially and within a word) correctly identified a consonantal slot.
However, the features of the adult target were not yet established in their productive
inventory. Their solution to realizing this empty slot was to fill in the [sonorant]
specification by default which necessarily surfaces as /j/ because of its syllable
position. Alternatively, it could be hypothesized that the [sonorant] feature spreads
from the following vowel to the preceding empty slot. However, the default segment
hypothesis is more appealing in this case since children often have a frequent segment
which is robust in their phonological inventories for a time. The minimal feature
specifications required by these default segments cannot always be provided by the
spreading of features from adjacent segments.
The feature [-(-continuant] in figure 14 is appended to the root node using a
dashed line to indicate that it was not established in all word positions. Recall from
the segment inventories presented above, that [+continuant] was only established in
syllable-initial-within-word and final word position. This branch had not yet been
established in initial word position. The same notation is used for '+complex' which
was not established in initial position.
Up to this point, it has been possible to describe the twins' phonological
inventories at the outset of this project by simply stating the established branches of
their productive hierarchy. That is, in every case thus far, the twins' surface
realizations of the adult targets result from the fact that they had not yet established
44
ROOT ROOT
([•fcontinuant])
[consonantal] [consonantal]
[+continuant]
PLACE /
(PLACE)
labial (coronal)
([+distributed])
Figure 15 The twins' realizations of word-initial HI (left) and word-final /9/ (right) with unestablished nodes marked in parentheses.
certain branches of the adult feature geometry. This finding is illustrated in figure 15.
The features in parentheses are those which needed to be established in order for the
twins' surface realizations to match the adult target phoneme. The exception to the
above description arises in the case of Ihl and HI, where the default segment surfaces
(although the surfacing of [j] for HI could also be accounted for by saying that
[consonantal] has not yet been established, together with the specification
[sonorant]). The case of /r/ surfacing as [w], however, does not have as simple, or as
satisfying, an explanation.
ROOT
([consonantal])
[sonorant]
PLACE
Figure 16: The nonlinear specification of the feature changes required to realize /r/ as [w]. (Underlined features are those which surface in the twins' realization.)
45
In order for the twins to realize /r/ as [w] one needs to state that the [consonantal]
feature is not yet established in the environment of [sonorant]. Thus far, the same
argument applies to the adult target HI. In the case of /r/, however, it is not [j] that
surfaces but [w]. The minimal specification required for/w/ includes the terminal
feature [+round] dominated by the 'labial' node. In essence, the twins were not
realizing the [+distributed] feature of the adult target and instead were acknowledging
the redundant secondary features of /r/ (see figure 16). The difficulty with this
argument is that redundancy rules do not fill in the full specification of phonemes until
very late in the derivation (in the twins' case the default segment is filled in before
redundancy rules are applied). Hypothesizing that full specification is complete earlier
in the derivation is undesirable because of the loss of simplicity in the explanation and
the increased burden on learnability. A better explanation for the /r/~>[w]
phenomenon does not present itself at this time (see, however, the concluding chapter
of Bernhardt, 1990).
Determining Targets for Remediation
Goals for the segmental condition of this project were determined based on a
comparison of the adult feature geometry for English, illustrated in figure 6 (see p. 16),
and the twins' established hierarchy described above. As previously mentioned, the
[+continuant] feature needed to be established in initial position for all fricatives. The
terminal features [-anterior] and [+distributed] under the 'coronal' place node were
both undeveloped at the outset of this project. One could say that the twins'
production of [ds] and [ts] for the affricates in syllable-initial-within-word and word-
final positions is evidence of the designation 'complex'. Recall that Bernhardt (1990)
inserted this mnemonic simply as a way of working around the controversy that exists
in the phonological theory literature regarding the feature specification of affricate
46
segments. The twins had not yet established this 'complex' specification in word-
initial position. Finally, the subjects of this project had not established the feature
[consonantal] in the presence of [sonorant] in word-initial position as is required for
the realization of both PJ and /r/.
Based on the undeveloped branches of the twins' established feature hierarchy,
segmental pairs for remediation were chosen which allowed for the comparison of
targeting lower features of the adult geometry with higher ones. Individual session
objectives are listed in Appendix 4. The segments /h/ and HI were initially targeted
with Subject 1 who was randomly assigned to the segmental condition. The minimal
specification of /h/ is [consonantal] [+continuant]. All [sonorant] segments are
redundantly [+continuant]. Since the twins were producing [j] for /h/, the feature
[•fcontinuant] was already established and only [consonantal] remained
unestablished for the specification of /h/. The feature that the twins needed to
establish in order to acquire /h/, then, was [consonantal]. This feature was well
established for consonants whose place of articulation is in the oral cavity, but still
needed to be acquired for this laryngeal fricative. The teaching of the segments /h/ and
HI allowed the acquisition of the feature [consonantal], the salient feature for /h/, to be
compared with [-fcontinuant], required for HI in word-initial position. Notice that in
medial and final word positions the comparison is between the acquisition of
[consonantal] and the 'labial' place feature since [+continuant] is already established
here.
Despite the fact that different nodes are being compared depending on word
position, the prediction remains the same. The feature [consonantal] occupies a
higher position in the feature hierarchy than [+continuant] and is, therefore, expected
to emerge earlier. Recall McCarthy's (1988) claim that [consonantal] and [sonorant]
are the highest features in the geometry because they actually form the ROOT node
47
while the manner nodes, [+continuant] and [+nasal] are only appended to it. In
segmental terms, then, fhf was expected to emerge before Ifl.
In syllable-initial-within-word position training the production of Ihl and Ifl
allows for the acquisition of [consonantal] and 'labial' to be compared. As with word-
initial position, Ihl is expected to emerge before Ifl because [consonantal] is less
embedded than 'labial'.
The difference in the acquisition of Ifl due to word position leads to interesting
speculations regarding the difficulty of the learning task. One wonders if it is easier to
establish the feature [+continuant] while maintaining (essentially) the same place of
articulation, or whether it is easier to develop the 'labial' place node once
[+continuant] has already been established.8 It should be noted that 'labial' was
already established in medial and final word positions as an obstruent; the difficulty is
in establishing 'labial' together with [+continuant] to create Ifl. Based on the
"embeddedness" of these features, the acquisition of Ifl in word-initial position should
be easier, since [+continuant] is directly attached to the root node. Conclusions
regarding the acquisition of /h/ and Ifl will be discussed below.
The second cycle of Block 2 compared the acquisition of /dg/ and /J/ with that of
hi and If/. A valid criticism of this choice of targets points out that Ifl has the unfair
advantage over the other segments because it had already received three cycles of
therapy. Since essentially no progress on Ifl was made during this training time, it
was decided that pairing the labio-dental fricatives with the alveo-palatal segments
might provide some interesting data. The voiced cognate of Ifl was added to the
training task with the hope that the increased vibration of the lower lip against the
8 Note that a separate 'labio-dental' place of articulation is not required, since English has no phonemic bilabial fricative. The 'labial' node is sufficient for the minimal specifications of both bilabial and labio-dental places of articulation.
48
teeth because of voicing would make this pair of targets more salient for Subject 1.
Since all four segments have a continuant component in their specification (affricates
are considered here as sequences of [-continuant] [+continuant]) and this is the only
branch required for the twins' realization to match the adult target in word-initial
position, no comparison can be made between lower and higher features. In medial
and final word positions, however, where the subjects realize HI as [s], establishing
the 'labial' place node can be compared with developing [-anterior]. In this case, the
feature hierarchy predicts that 'labial' would be easier to acquire because it is less
embedded than the [-anterior] feature of the 'coronal' place of articulation.
Results.
The first mini probe was administered after eight therapy sessions, which
targeted first /h/ and then /f/. This mini probe, which assessed any generalization of
treatment targets using a single word and connected speech production task, found
that no acquisition of targets had occurred by this time. The compiled mini probe data
for segmental targets is presented in graphed form for both subjects in figures 17 and
18 (see pages 49 and 50). Percentage accuracy figures are based on the combined
results of imitated forms and spontaneous forms. Recall that mini probes took place
every three weeks (or twice each block) throughout the project.
By the second mini probe at the end of Block 1, a minimal increase in the
accuracy of producing /h/ and /f/ is recorded. Given that the percentage accuracy of
pronunciation in subsequent mini probes for HI drops off, the slight increase in accuracy
at the end of Block 1 is considered coincidental. As is illustrated in figure 17,
however, the accuracy of /h/ production continued to increase until it reached 100% at
mini probe #5.
The acquisition of HI clearly followed that of Ihl for both Subject 1 and Subject 2.
As illustrated in figure 17, essentially no generalization to novel single words
49
containing HI, nor to the story retell activity was noted until mini probe #6, at the end
of Block 3 of the study. Just five days prior to this last mini probe, Subject 1 greeted
the author with the question "Can I be first today?" This author suspects that a
breakthrough had occurred a day or two before and Subject 1 had planned this greeting
with a perfectly articulated first, to show that he could finally produce the target that
had been the focus of therapy for so long. Results on the sixth mini probe revealed
87% accuracy on single word targets and 67% accuracy on the story retell task for HI
(hence the 72% combined result plotted in figure 17). It should be noted that the first
cycle of Block 3 did not target HI or /v/, but trained the syllabic targets of Subject 2 and
the alveo-palatal targets (see session objectives in Appendix 4). Based on her
results with singleton subjects, Bernhardt (1990) suggests that alternating syllabic
and segmental goals is beneficial for acquiring both types of targets. Other
explanations for this late breakthrough of HI present themselves. It is possible that
the one-and-one-half cycle break from targeting the labio-dental fricatives allowed
Subject 1 to pay attention to the occurrence of these segments in natural conversation
and subsequently generalize their production to conversation himself (Hodson &
Paden, 1983). Alternatively, success with the syllabic /s/-cluster targets effectively
established the [-fcontinuant] feature in word-initial position, which may then have
transferred to the acquisition of HI in this position. Just which of these explanations
holds in Subject l's case cannot be concluded from the data here; quite possibly the
sum of all three explanations was required before HI could generalize to spontaneous
conversation.
As previously outlined, it was speculated that HI in word-initial position would
be more easily acquired because the needed [-fcontinuant] feature was less embedded
than the 'labial' place node required for HI in medial and final word positions. Although
HI was acquired in spontaneous conversation in all word positions simultaneously, its
production in initial training sessions was superior in medial and final word positions.
0 1 2 3 4 5 6
m i n i p r o b e
Figure 17: Graph of the segmental targets based on mini probe results for Subject 1.
0 1 2 3 4 5 6
mini probe
Figure 18: Graph of the segmental targets based on mini probe results for Subject 2.
52
Subject 1 had no difficulty approximating the correct production of Ifl during imitation
tasks when the target was not word initial. He tended to produce a labio-dental stop
following a word-initial /f/ before articulating the remainder of the word. At the end of
Block 2, Subject 1 changed strategies for a single session and produced [sp]
sequences for each /f/-initial word. Whether this production was influenced by the
syllabic goals Subject 2 was targeting at the time, or whether Subject 1 had decided
that [+continuant] could only be established with a 'coronal' place of articulation
followed by a stopped 'labial', is unknown. Interestingly, Subject 2 produced the same
[sp] for all /f/-initial words on the mini probe administered two days after Subject 1
had attempted this strategy.
Based on the finding that the production of If/ in word-final and medial positions
was easier to train than in word-initial, we would have to conclude that establishing
the more embedded 'labial' place node in the presence of established [+continuant] is
easier than developing [+continuant] itself. This finding appears to counter the
predictions made by the feature geometry. Bernhardt (1990) discusses similar
findings with her subjects and speculates that the [+continuant] feature must be
learned separately for each of the PLACE nodes and the LARYNGEAL node.
Continuancy, therefore, is not acquired "across the board," but must be established
individually for labial, coronal and dorsal segments. The data here supports the claim
that continuancy is most easily established with a dorsal consonant place of
articulation.
It can be concluded, based on the findings that Ihl was acquired before Ifl, that
the feature geometry—as described in chapter 2—is supported by clinical data. As
predicted, the segment whose salient feature occupied a higher position in the feature
geometry was acquired before the segment whose salient feature filled a more
embedded position. Training the production of the targets /J/ and /dg/ and comparing
acquisition results with the results of intervention targeting Ifl and /v/ allowed the
53
development of the 'labial' place node to be compared with the development of the
terminal feature [+anterior]. The feature geometry predicts that 'labial' will be
acquired first. Recall that this comparison could only be made for syllable-initial-
within-word and word-final data because the same feature, [-fcontinuant], was being
established when training all these targets in word-initial position.
The results for Subject 1 clearly support the predictions of the feature
geometry. At mini probe #6, he achieved 75% accuracy on /f/ productions and 58%
accuracy on /v/ productions. Neither /J/ nor /dg/ had shown any generalization in novel
single-word targets or in spontaneous conversation at this time. It should be noted,
however, that the affricate, /tj/, whose acquisition was expected to generalize from
that of HI and /dg/, was produced with 60% accuracy for single-word stimuli only (three
correct productions out of a possible five). Conversation level for /tj/ could not be
tested at this mini probe because of the abundance of targets which needed to be
assessed. Figure 18 illustrates that the described findings are supported by
Subject 2's data. At both mini probe #5 and #6 Subject 2's percentage accuracy for
producing /f/ exceeded that of /JV and /dg/. The fricative /v/ was never targeted with
this subject; however, at the final grand probe following Block 3 of therapy, Subject 2
was producing /v/ with approximately 50% accuracy in all word positions. Based on
the acquisition of labio-dental fricatives as compared with alveo-palatal fricatives and
affricates in this study, the predictions of the feature geometry are borne out. For both
subjects the 'labial' place node was established before the more deeply embedded [-
anterior] feature.
Conclusions
Returning to the three questions outlined at the beginning of this chapter, it can
be concluded that the results of the segmental condition of this study provide evidence
for choosing targets for remediation based on the nonlinear feature geometry. The
54
feature [consonantal] was acquired before the more embedded [+continuant] feature.
Since /f/ was more easily acquired in word-final position, one could conclude that the
'labial' node is easier to acquire than [+continuant]. Such a conclusion would not
support the feature geometry because the 'labial' place node is more embedded than
[+continuant]. The hypothesis was presented, however, that continuancy .must be
separately established for each place of articulation. Comparing the acquisition of
manner nodes with place of articulation nodes, then, is not in accordance with this
hypothesis. It can be concluded however, that the acquisition of the 'labial' place node
for HI occurred before [+anterior] of the alveo-palatal segments was developed. This
conclusion provides evidence in favor of choosing targets based on the feature
hierarchy.
The second question addressed the issue of generalization of a targeted
segment to other segments with similar minimal feature specifications. The data
provides some evidence that generalization occurred. As described above, targeting
III and /dg/ generalized to the emergence of AJ/ for both subjects. Training the
production of /f/ and /v/ with Subject 1 did not lead to the acquisition of any other
segments (/s/ in initial position would have been a possibility). However, /v/ was
beginning to emerge at the end of the study for Subject 2, who had only received
training on HI. Generalization, then, was only evident in voiced or voiceless cognates
of trained targets; acquisition of targets beyond this immediate sound class did not
occur (within the time frame of this project).
The third question of investigation focussed on the possibility of Subject 2, who
was placed on the syllabic condition, spontaneously acquiring the segmental goals of
Subject 1. Interesting results were found in this area. Subject 2 acquired both /h/ and
HI without any direct training. Surprisingly, this acquisition occurred before Subject 1
had acquired either of these targets! As illustrated in figure 17, Subject 1 made slow
but steady progress on establishing Ihl until mini probe #5, when he reached 100%
55
accuracy at the conversational level. Subject 2 achieved 64% accuracy for the
production of /h/ at mini probe #3 when Subject 1 achieved only 38% accuracy. Similar
results were obtained for /f/. The day before mini probe #5 Subject 2 began producing
HI in spontaneous conversation; Subject l's request to be first did not occur until one
week later. These results are reflected in the data of mini probes #5 and #6. Whether
Subject 2's acquisition of HI occurred through generalization from his /s/-cluster syllabic
targets, or whether HI was acquired because Subject 1 was attempting this target,
cannot be conclusively determined from the data here.
In summary, then, the data described in this chapter provides evidence
supporting feature hierarchies, some generalization of trained targets to related
segments occurred, and spontaneous acquisition of segmental targets by the twin
placed on the syllabic condition occurred.
56
CHAPTER 5
THE SYLLABIC CONDITION
Initial assessments of phonologically delayed children often describe deficits
that affect more than a single segment. Clinicians using a phonological process
analysis often include terms such as 'cluster reduction', 'weak syllable deletion', and
'reduplication' to describe these types of phonological errors. In addition, phonological
process descriptions such as 'final consonant deletion', 'assimilation' and 'stopping of
fricatives in syllable- initial position' capture difficulties with the production of single
segments in certain word positions. Both of these kinds of processes refer to
difficulties affecting phonological development at not the segmental but the syllabic
level of representation.
Recall from chapter 2 that the basic syllable is the CV unit. The universality of
this syllable shape is supported by both cross-linguistic data, and the predominance of
CV syllables in the earliest utterances of typical language learners and in the
utterances of phonologically disordered children. In order for development to proceed
beyond this "default" syllable shape, the language learner is required to mark those
more complex syllable shapes evident in her linguistic environment. Prior to
developing these advanced syllable units, the child must fit complex lexical items into
her more basic existing syllable inventory. This stage of development is typically
described using the processes and rules cited above. If, for example, a child attempts
saying the word truck but only has CV and CVC syllable shapes in her inventory, then
truck will surface as [L\k] assuming no other phonological difficulties affect the
production of this target. A process analysis of such an error would describe the error
57
as 'cluster reduction'. The view supported in this paper, however, holds that the
language learner has not "reduced" anything, she simply has not yet developed the
branching required at the syllabic level to correctly realize the adult target.
The second kind of syllabic process typically referred to in phonological process
assessments accounts for the acquisition, or lack thereof, of segments or groups of
segments in certain word positions. The subjects of this study, for example, realized
HI in word-final position as [s], but in word-initial position HI surfaced as [p]. In actual
fact, at the outset of the project, the twins had no fricatives in their word-initial
inventory and a phonological process such as 'stopping of word-initial fricatives' would
have adequately described their production. A better explanation (as opposed to the
process description-) holds that the [+continuant] node had not yet been established in
their word-initial inventory. Phonological difficulties such as these provide evidence
for the interaction of the segmental and syllabic tiers during phonological acquisition.
As with intervention under the segmental condition, the syllabic condition of
this project led to the investigation of three questions. Recall from chapter 2 that two
main theories are currently being developed in the field of linguistics to account for the
organization of phonemes into syllables. The primary question in the syllabic
condition investigated whether training following the moraic approach or the onset-
rime approach would lead to the faster acquisition of therapy targets. This faster
acquisition could reflect a "match" between the theoretical hierarchy and the child's
mental representation of the syllable's organization. As with the segmental condition,
this central inquiry led to two further questions. The second question, then, addressed
what spontaneous generalization to other syllabic goals would occur, and if such
generalization could provide independent support for either moraic or onset-rime
theory. And finally, the third question focussed on whether Subject 1, placed on the
segmental condition, would acquire any of the syllabic goals of Subject 2 without direct
intervention. Depending on which targets were acquired, such spontaneous
58
development could provide support for either the moraic or the onset-rime syllable
theories. Before discussing the results of intervention within the syllabic condition,
the twins' syllabic inventories at the outset of the current study will be described.
The Starting Point
It was hypothesized in chapter 2 that the syllabic level of phonological
development could be more basic—that is, less embedded—than the segmental level.
In agreement with this hypothesis, phonologically disordered children with restricted
syllabic inventories are usually considered to be more severely disordered than those
showing deficits at only the segmental level. The twin subjects of this study were not
severely disordered and, as expected, they did not have severely restricted syllabic
inventories. At the time of the initial assessment, (please see the grand probe #1
data presented in Appendix 3) the CVC syllable was firmly established and it was
found that the twins had no difficulty stringing these CVC units together to match
mono-, di-, and polysyllabic adult targets. In syllable- and word-final positions both
twins were able to produce clusters of two and three consonants in words such as ajlc
and ants. Syllabic deficits were evident, however, in word- and syllable-initial
positions where the twins' productions only allowed, at most, a single consonant to
surface.
At the time of the first grand probe, sequences of a consonant followed by
either /!/, /r/ or Av/ (as in plum, truck, or quick) predictably surfaced as a singleton
obstruent consonant for both of the twins. Producing truck as [tAk], as described
above, was typical for the twins. Consonant clusters with /r/, IM and /w/ in which the
initial consonant was a fricative, were realized as a stop consonant, since continuancy
was not yet established for the twins in word-initial position. Hence, throw was
pronounced [po] and slide as [taid]. Clusters with /s/ followed by a non-liquid or glide
consonant surfaced without the /s/. For example, snake was produced as [neik], spot
59
as [pat], stop as [tap] and skinny as [kmi]. The /sw/ cluster provided the only noted
difference between the phonological inventories of the two twins. Subject 2 treated
/sw/ as a /Cw/ cluster rather than a /sC/ cluster. As such, the /w/ was not realized and
the /s/ surfaced as the noncontinuant [t]. Subject 1, however, grouped /sw/ with the
/sC/ clusters, which resulted in the /s/ not being realized and the /w/ surfacing. The
grand probe word sweater was pronounced [tedr] by Subject 2 but [wedr] by
Subject 1. This difference in syllabic constraints led to interesting differences in the
twins' acquisition of the /sw/ cluster, which will be further discussed below. Similar to
/sw/, the cluster /si/ was not treated as an /sC/ combination. If the twins had grouped
/si/ with the other /s/-clusters, one would expect [j] to surface, since HI was
pronounced [j] and /s/ was not produced for these clusters. The fact that [t] was the
surface realization of /si/ indicates that this cluster was grouped with the /CI/ clusters
where HI was not realized and only the consonant [C] surfaces (in this case [t] for the
target /s/).
The second type of syllabic restriction—where positional constraints are
evident in the production of segments or groups of segments-were also evident in the
phonological inventories of the twin subjects of this study. As already mentioned, the
[+continuant] node was only established in syllable-final position. The only
productive fricative in this position was /s/. It was difficult to determine whether the
voiced cognate /z/ was productive in the twins' inventories because of the natural
occurrence of word-final devoicing. Based on auditory judgment, vowels and
consonants preceding a targeted word final /z/ were sufficiently lengthened to mark a
contrast between /s/ and Izl. In syllable-initial position all fricatives surfaced as stop
consonants.
Production of the liquids HI and hi reflected syllabic constraints since they were
established only in word-final position at the outset of this project. The segment /r/
was firmly established in word-final position but surfaced as [w] at the beginning of a
60
word. The correct production of /r/ in syllable-initial position within a word supports
the ambisyllabic nature of liquids within words. At the time of the initial assessment,
HI was emerging in word-final position but surfaced as [j] in both word- and syllable-
initial position.
Determining Targets for Remediation
Determining therapy goals within the syllabic condition of this project was a
relatively straightforward task given the limited number of syllabic deficits evident in
the subjects' phonologies. The choice of targets was limited to syllable- and word-
initial consonant clusters and certain segments showing positional constraints. A
further restriction on choosing goals for remediation within the syllabic condition
required target clusters and segments to be made up of segments established in the
twins' inventory. Since /s/, /r/ and HI were all at least emerging in word-final position,
any of the /sC/, /Cr/ or /Cl/ clusters presented options for therapy. In addition, all
segments (except for /s/ and /9/) that cluster with /w/ were well established. Hence
/Cw/ clusters were also a possibility for therapy. Of the options, /sC/ and /Cw/
clusters were chosen as intervention targets for this study.
Four reasons supported the choice of /sC/ clusters for remediation. First, the
abundance of words with initial /s/-clusters in the English language meant that the
twins' communicative success was greatly diminished by not being able to produce
these clusters. This effect appeared to be greater in the case of /s/-clusters than with
either /CV or /Cr/ combinations. Second, /s/-clusters tend to emerge earlier than HI- or
/r/-clusters in the inventories of typical children, which suggests that they may be
easier to acquire. Third, during the period of initial assessment it was found that the
twins were more stimulable for the correct production of clusters with I si than those
with HI or /r/. Finally, the possibility existed that establishing /s/,-clusters in the twins'
productive inventories would generalize to the acquisition of other segments—
61
specifically, that establishing the [+continuant] feature for /s/ in initial clusters would
enhance the emergence of the class of singleton fricatives.
Of the seven /sC/ combinations, four were chosen for direct intervention and
three remained untreated to see if spontaneous acquisition would occur. The clusters
/sn/ and /sp/ were targeted in therapy using the moraic approach, while /st/ and /sk/
followed the onset-rime approach. The details of each training approach will be
described in the next section. In order to keep the two approaches approximately
equal in difficulty, clusters with similar features were assigned to opposite conditions.
In the case of /s/-clusters, /sn/ and /st/ are similar because /s/ is paired with a coronal
segment in each combination. These two clusters are unequal, however, because /s/
is part of the syllable in the case of /sn/ but is considered to be 'extrametrical' in the
case of /st/.
An explanation of the notion 'extrametricar is required. Saussure (1915) was
the first to notice the general tendency for syllable constituents to be arranged
according to their sonority. Kiparsky (1979) claims that the least sonorous elements
of a syllable fall at the margins while the most sonorous make up the syllable centre or
peak. The sonority hierarchy from least sonorous to most sonorous, as defined by ,
Kiparsky (1979), takes the form: stops~>fricatives—>nasals—>liquids—>
glides—>vowels. When the arrangement of segments does not follow this hierarchy,
violating segments are termed extrametrical, provided they fall at the margin of the
syllable (Hayes, 1982).9 Designating certain elements as extrametrical redefines the
edge of the syllable, allowing the application of phonological rules to "overlook" edge
segments. Rules requiring reference to extrametrical constituents are widely
y It should be noted that extrametricality is not restricted to single segments but may refer to any single edge constituent including segments, morae, syllables and feet (McCarthy & Prince, 1988).
62
documented cross-linguistically (e.g. Kiparsky, 1979; Cairns & Feinstein, 1982;
Hayes, 1982; Harris, 1983).
Returning to /s/-clusters, it can be seen that when compared to the sonority
hierarchy, /s/ followed by the stop consonants /p/, /t/, or fkf would be considered as
extrametrical. The remaining /s/-clusters, /sm/, /sn/, /si/, and /sw/, follow the sonority
hierarchy by having the least sonorous element at the syllable edge; /s/, therefore, is
not designated as being extrametrical. In addition to determining whether the moraic
or the onset-rime approach in therapy would lead to the faster acquisition of targets,
the training of /s/-clusters would determine if extrametricality affected their
acquisition. Since the sonority hierarchy is considered to make up part of universal
grammar, the theory predicts that /sn/ would be easier to acquire than /sp/, /st/ or /sk/,
where /s/ is extrametrical. In this sense, the moraic condition, which included /sn/ and
/sp/, could be considered easier than the onset-rime condition, which included /st/ and
/sk/.
In addition to /s/-clusters, /Cw/-clusters were also targeted in the syllabic
condition. All the consonants that combine with /w/ were well established in the
twins' inventories, with the exceptions of /sw/ and /6w/ (the latter cluster does not
occur in words commonly used by 5 year-olds!). The targets /kw/ and /tw/ were
chosen for direct intervention while /sw/ served as a baseline for generalization (the
acquisition of /dw/ was not monitored since the only word likely to be part of a
kindergarten lexicon in which it occurs is dwarf). The cluster /tw/ was assigned to the
moraic condition while /kw/ was targeted under the onset-rime condition.
After three cycles, direct therapy of /s/-clusters was discontinued and the
segments /z/ and HI, along with /tw/ and /kw/, were targeted. Recall that /z/ and HI
were established in word-final position only and, therefore, reflect positional
constraints. Differentiating the training of these singleton targets according to the
moraic or the onset-rime approach proved to be more difficult than for cluster targets.
63
Details of these training differences, however, will be described in the following
section. As previously mentioned, targeting singleton consonants within the syllabic
approach reflects the interaction between the syllable and segmental tiers of the
phonological hierarchy. The training and acquisition of these segments allows not only
the two syllable approaches to be compared, but also acquisition results to be
analyzed based on the feature content of the targets. Both /z/ and HI are characterized
by two features appended to the root node in their specifications and, therefore, would
appear to be equivalent in difficulty. In actual fact, the [consonantal] [sonorant]
combination of /l/ is more marked (fewer segments require this specification) than the
[consonantal] [+continuant] combination of /z/. This marked status of HI is borne out
when cross-linguistic data is analyzed. Based on features, then, it was predicted that
M would be acquired before HI.
The /sC/- and /Cw/-clusters made up the goals for the first three cycles (or first
one-and-one-half blocks) of the intervention project, while Izl, HI and /Cw/-clusters
were targeted in the fourth cycle. The individual session objectives for Subject 2, who
was assigned to the syllabic condition, are outlined in Appendix 4.
Treatment
Before discussing the results of treatment within the syllabic condition, therapy
following the moraic approach will be contrasted with therapy following the onset-rime
approach. As outlined in Chapter 2, the moraic theory of syllable structure holds that
onset cluster constituents are appended individually to the syllable node.
Consequently, the cluster was treated as two units and minimal pairs such as nap-
snap and pot-spot served as the basis of training. Treatment under this condition
allowed the clinician to emphasize the initial /s/ by lengthening it considerably when
modelling target forms. Subject 2 responded well when instructed to "put the magic S
on." Similarly, training of /tw/, which also followed a moraic approach, contrasted
64
pairs such as wig with twig. Subject 2 could easily produce the /w/-initial words of the
minimal pairs and, when instructed to produce A/ before these, he was easily able to
pronounce the consonant cluster.
The onset-rime theory of syllable organization holds that constituents of an
onset cluster form a unit in opposition to the rest of the syllable (the rime). In this
case /s/ and the following obstruent could not be separated from each other in therapy
and needed to be contrasted with the remainder of the word. The /sk/-cluster in the
word skate, for example, was presented in two ways: either ale. was contrasted with
skate or the /sk/ unit was repeated several times before saying the target word (e.g.
[sk-sk-sk-skeit]). For some words production was facilitated by moving a word-final
/sC/-cluster to wOrd-initial position. For example, saying ask followed by al several
times simulates /sk/ in word-initial position and eventually sounds like a scat. After .
several repetitions of a scat Subject 2 was encouraged to drop the a and produce scat
on its own. The teaching of /kw/ followed similar principles. In this case /kw/ was
pronounced [ku] followed by the remainder of the word (e.g. quick was presented as
[ku + ik]). The discussion under Results provides further rationale for this teaching
approach for the /kw/ cluster.
The presentation of the singleton consonant targets /z/ and IM according to
moraic or onset-rime approaches, differed only at the initial stimulation or elicitation
stages. Both theories allow the onset target consonant to be taught in isolation and
opposed to the remainder of the syllable, the rime in the case of onset-rime theory or
the mora or weight unit in moraic theory. In order to maximize the differences
between approaches, however, the targeting of /z/ in initial position, which followed
the moraic approach, did not allow the consonant to be separated from the following
weight unit. Following this approach, /z/ was initially elicited in CV syllable units
before moving on to CVC words (e.g. zip., zap, zoom, etc.). Eliciting the production of
IM in initial position followed an onset-rime approach. Recall that IM in word-final
65
position was emerging at the outset of the current project. By the third cycle of
therapy, its production in this position was well established. As a consequence,
training /l/ in word-initial position involved moving a word-final A7 first to an
ambisyllabic position and then to a syllable onset as in pill-->pillow->low. A basic
premise of the onset-rime theory is that syllable onsets should be maximized or
created wherever possible, and it is this principle which is being emphasized when
requiring Subject 2 to move an established coda consonant to a syllable onset position
(Hyman, 1985). The results of these teaching methods for /z/ and /V will be discussed
in the next section.
Results
Target Presentation Session
Review Session
Review Session
Combined Results
/sn/ 78.0 63.6 22.2 63.8
/sp/ 60.7 34.5 43.3 46.0
Aw/ 64.2 10.0 38.5 52.6
Table 1: Percentage accuracy achieved by Subject 2 for clusters targeted in therapy based on the moraic theory of syllable organization.
Target Presentation Session 1
Presentation Session 2
Review Session
Combined Results
/st/ 0.0 4.4 6.7 4.4
/sk/ 0.0 2.2 0.0 1.9
/kw/ 95.2 33.0 45.7 57.8
Table 2: Percentage accuracy achieved by Subject 2 for clusters targeted in therapy based on onset-rime theory.
66
Tables 1 and 2 present the combined imitation and spontaneous data of the
first cycle of therapy for Subject 2. The percentages achieved during the initial cycle of
therapy most accurately reflect the effectiveness of the training or stimulation
approaches used in therapy. In general, Subject 2 was able to produce all of the
targets quite accurately during subsequent cycles. He needed, however, to generalize
this accuracy to spontaneous conversation. Cycles 2 and 3, therefore, focused on
providing opportunities for Subject 2 to produce targets during relatively natural
conversation and the differences in therapy which were evident during the initial
training of targets were no longer present. More than one percentage is provided for
each target cluster because a review of moraic goals took place on the fourth and
eighth sessions of the cycle. Onset-rime goals, however, were targeted over two
sessions and reviewed on the eighth session of the cycle. Appendix 4 presents a
schematic representation of individual session objectives.
Comparing the percentage accuracy for the initial attempts at producing
/s/-clusters, Subject 2 was far more successful in therapy when the moraic approach I
was followed. Three main reasons present themselves as explanations. First, it is
possible, as suggested earlier, that the clusters taught using the moraic approach
were actually easier to produce than those taught using the onset-rime approach.
Since /s/ in /sn/ is not extrametrical and the cluster instead follows the sonority
hierarchy, its production may be easier than either /st/ or /sk/. Bernhardt (1990) found
that all of her singleton subjects had difficulty acquiring the /st/ cluster. She
speculates that this is because the segments of the /st/ cluster are homorganic and
because /t/—Subject 2's surface realization of this cluster—is the unspecified (in terms
of features) default segment in English (please see chapters 2 and 4 for definitions of
underspecification). In essence, the difficulty lies, first, in allowing something other
than /t/ to surface and, second, in establishing [+continuant] in word-initial position.
In other words, realizing a target segment or cluster with the default coronal is more
67
difficult to correct than if some other segment is substituted. Comparing the
learnability of /sp/ with /sk/, it is possible that /sk/ is a more difficult target because it
requires two places of articulation on the single tongue articulator, while /sp/ is
produced using two separate articulators.
A second possible explanation of the higher percentages acquired while
intervention followed the moraic theory is that the moraic approach is simply easier to
apply in therapy than the onset-rime approach. During the therapy sessions, the
clinician sensed that the presentation and modelling allowed by the onset-rime
approach did not reflect the normal usage of target words, but simply provided an
ad hoc method of eliciting the target cluster. Subject 2 did not appear to transfer this
stimulation technique to the production of target words in subsequent therapy tasks.
In addition, the onset-rime approach did not allow the correct pronunciation of /s/-
clusters to be contrasted with Subject 2's usual production of /st/ and /sk/ words. The
moraic approach, for example, allowed the clinician to elicit a correction by asking:
"Did you say go! or spot?" The moraic approach also allowed the clinician to
emphasize the /s/ when modelling /s/-clusters by lengthening it and by increasing the
audibility of the frication. Since /s/ could only be produced in combination with the
following consonant when teaching clusters using the onset-rime approach, the same
elicitation and modelling techniques could not be used. Unfortunately, the current
project only attempted targeting clusters using the onset-rime approach with one
subject. Had more subjects been used, it is possible that more innovative and
facilitating techniques following this approach would have been discovered. Bernhardt
(1990) presents a comparison of the moraic and onset-rime approaches using six
subjects and concludes that, based on quantitative data, there is no significant
advantage in using one approach over the other. She does, however, report qualitative
differences between using the two approaches for certain subjects.
68
A third explanation for the advantage observed when teaching was based on
the moraic approach reflects the distribution of segments over therapy sessions.
Appendix 4 outlines the cluster objectives for individual therapy sessions. Each cycle
consisted of nine treatment sessions. Of these, three-and-one-half sessions targeted
clusters following the moraic theory and three-and-one-half session followed the
onset-rime theory. The eighth session of the cycle reviewed all the targets following
designated training approaches, and the ninth session was a mini probe which
assessed the acquisition of targets in novel stimuli. As shown in Appendix 4, this
distribution meant that the goals of the onset-rime approach were targeted in two half
sessions. However, Subject 2 had great difficulty changing goals in the middle of a
session. This distribution, therefore, may have reduced the percentage accuracy
figures and unfairly placed the onset-rime condition at a disadvantage where the
acquisition of s-clusters is concerned. As noted earlier, if more subjects had been
trained on the same syllabic goals, it would have been possible for cluster targets to
be assigned to the opposite condition, and more definite conclusions regarding the
advantage of one treatment approach as opposed to the other could be drawn.
The data for /Cw/ clusters from the first cycle of therapy reflects slightly higher
percentages when the elicitation of targets followed the onset-rime approach,
especially when the individual session data, as opposed to the combined data, is
compared. Therapy in the onset-rime approach presents /Cw/ clusters using an initial
/Cu/ syllable. Such a technique encourages the use of epenthesis, a facilitating step
that many typical children use when acquiring these clusters. According to onset-rime
theory, maximizing CV or onset-rime units is desirable (recall the default status of the
CV syllable); hence, separating a cluster with an epenthetic shwa to create a new
onset-rime unit is a logical operation for a language learner following the principles of
this theory. Adding a weight unit, however, as would be required to account for
epenthesis using a moraic organization for the syllable, is not a logical explanation
69
Target Presentation Presentation Session 1 Session 2
Review Session
Combined Results
/z/(m) 28.1 62.1 41.7 43.5
HI (o-r) 34.6 30.6 38.9 33.0
Table 3: Percentage accuracy figures for the initial cycle of targeting /z/ (moraic approach) and HI (onset-rime approach).
within moraic theory. In summary, then, by training the use of epenthesis, the
accurate production of /kw/ was facilitated.
Table 3 provides percentage accuracy figures for the initial cycle of therapy
targeting the singleton segments /z/ and /l/. Recall that IzJ was targeted using a
moraic approach while the production of HI was trained following the onset-rime
approach in therapy. Based on the percentages presented above, it would appear that
using a moraic approach in initial elicitation stages is more facilitating than using an
onset-rime approach. Although this may be correct, there is insufficient data in the
current study to draw this conclusion. Further research that compares the two
training approaches over several segment pairs is required to verify this finding. It is
the impression of this author that the two syllabic theories simply allowed the target
structures to be elicited in different ways and that their differences were not significant
to the acquisition of the segments. Instead, the differences in the percentages above
may be better explained by referring to the feature content. From this point of view,
the earlier prediction that /z/ would be more easily acquired than HI is borne out.
Figure 19 illustrates Subject 2's acquisition of syllabic goals based on mini probe
results. It can be seen that /z/ was established after two cycles of therapy, while HI
was still emerging after three cycles of training. Whether the training approach used
with IzJ, or its feature content, or a combination of the two accounts for these results
can not be concluded based on the single subject data presented here.
Figure 20: Graph of the /s/-cluster data based on grand probe results for Subject 2.
72
The acquisition data (as opposed to the initial elicitation or training data
discussed above) presented in Figure 19 does not provide any further evidence that
would favor using one syllabic approach in therapy over the other. After three cycles
of therapy, all the /s/-clusters were beginning to emerge, including the untrained
targets /sm/, /sw/ and /si/, although the latter surfaced as [st]. It should be noted that,
the 11% and 20% correct for /st/ and /sk/ achieved at the second mini probe are based
on only nine attempts at /st/ and four attempts at /sk/. Because of the small number of
tokens, it cannot be concluded that these clusters were emerging at this time.
Figure 20 illustrates the acquisition of the group of /s/-clusters as
demonstrated in the grand probes, which occurred after every two cycles of therapy
(every six weeks). The grand probe results accurately reflect the spontaneous usage
of therapy targets because they were taken after a one week break from therapy
(which allowed any recency effects from therapy to be removed) and because the
grand probe sessions bore no relation to the usual structure of therapy. The elicitation
method used was natural and appeared to the twins to amount to a free play session.
By the fourth grand probe, /s/-clusters were emerging steadily, and the number
of these targets that surfaced as a singleton obstruent was decreasing. The single
word data presented in Appendix 3 shows that the first cluster to emerge for Subject 2
was /sn/, which was accurately produced at the time of the second grand probe. All
other /s/-clusters were emerging by the third grand probe, and their accuracy increased
by the fourth grand probe. The non-extrametrical status of /s/ in /sn/ clusters,
together with the fact that /sn/ was one of the four /sC/ combinations targeted in
therapy, probably accounts for the earlier emergence of this cluster.
Based on the /tw/ and /kw/ data at the time of the fourth mini probe, presented
in figure 19, one would think that the conclusion reached earlier—that the onset-rime
training approach used with /kw/ facilitated acquisition because it emphasized the use
of epenthesis—is inaccurate. However, it should be noted that any attempt at
— reduced
epenthesis
correct
1 2 3 4
grand probe
Figure 21: Graph of the /Cr/-cluster data based on grand probe results for Subject 2.
120
— reduced
epenthesis
correct
1 2 3 4
grand probe
Figure 22: Graph of the /Cl/-cluster data based on grand probe results for Subject 2.
75
producing /tw/ which realized two consonants was counted as being correct. At the
time of the fourth mini probe, every attempt at /tw/ was produced with epenthesis and
was judged as correct. As a result, the /tw/ data at mini probe #4 in figure 19 actually
provides support for using the onset-rime approach in therapy.
Figures 21 and 22 illustrate the grand probe data of Subject 2 for /Cr/ and /CI/
clusters. Before beginning the intervention project, both subjects were producing only
the initial consonant of these clusters (e.g. dress was pronounced [des]). At the time
of the fourth grand probe, however, these clusters were being produced as /Cw/
combinations since neither /r/ nor /l/ were firmly established in initial or cluster
position. The acquisition of clusters with /I/ and /r/, then, was doubly encouraged b y
targeting /Cw/-clusters. First, the use of epenthesis, as was trained when producing
/Cw/-clusters, generalized to the production of /CI/- and /Cr/-clusters (e.g. blue was
pronounced [bslu] and t r u c k as [ t u w A k ] ) . The percentage of tokens produced with
epenthesis b y Subject 2 for these clusters is presented in figures 21 and 22. Second,
t a r g e t i n g /Cw/ encouraged the [w] to surface for /r/ and DJ (see chapter 4 for an
explanation of the feature nodes involved in this production). This s u b s t i t u t i o n is
commonly f o u n d in children with developing phonologies and, therefore, allowed the
listener to better "guess" at what the twins were saying.
To this point no mention has been made of any acquisition of syllabic goals b y
Subject 1. All of the results outlined above are based on the results of therapy with
Subject 2, who was assigned to the syllabic condition. Recall from chapter 4 that
Subject 2 had spontaneously acquired all the segmental goals of Subject 1. The
reverse, however, d i d not occur. By the end of the second block of therapy (four
cycles), Subject 1 had only demonstrated four correct productions of /s/-clusters (three
correct productions of /sn/ at grand probe #3). As a result, the decision was made to
target /sC/- and /Cw/-clusters during the third block of therapy. The specific clusters
were /sp/, /st/, /sk/, /sw/ and /kw/ (see Appendix 4 for session objectives).
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The cluster /sn/ was not targeted because there was evidence of spontaneous
acquisition.
Figure 23 illustrates Subject l's acquisition of /sC/- and /Cw/-clusters based on
the mini probes administered in the middle and at the end of the third block of therapy.
The data at mini probe #5 indicates that of the /s/-clusters targeted in therapy, /sw/
shows the highest percentage accuracy. It should be noted that /s/ in /sw/, as in /sn/,
is not extrametrical. Although Subject 2 had no difficulty acquiring /sw/, based on mini
probe results this cluster did not appear to be "easier" than the other /s/-clusters. For
Subject 1, however, /sw/ did appear to be an easy cluster to learn. This ease of
acquisition may have resulted from Subject l's grouping of /sw/ with the /Cw/-
clusters. This organization meant that therapy focusing on both /s/-clusters and on
/Cw/ clusters was facilitating the acquisition of /sw/. In contrast with /sw/, the
clusters /st/ and /si/ appeared to the most difficult for Subject 1 to acquire. These
findings are in agreement with the acquisition results of Subject 2 and the same
explanation—that it is difficult for the language learner to realize something other than
the underspecified default /t/—holds here as well.
The results from mini probe #6 show that /kw/ was beginning to emerge in
Subject l's speech at this time. The data from grand probe #4, administered one week
after the sixth mini probe, showed no generalization to novel /kw/ words. However, at
this time 12.5% of the /Cr/-cluster words surfaced with two adjacent consonants (with
/r/ surfacing as [w]) while 25% of these targets were produced using epenthesis. As
with Subject 2, the teaching of /Cw/-clusters facilitated the acquisition of /Cr/-clusters.
The same effect had not spread to /Cl/-clusters by the time of the fourth grand probe.
Figure 23: Graph of the syllabic targets based on mini probe results for Subject 1.
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Conclusions
The principle question in the syllabic condition of this project investigated
whether therapy based on the moraic theory or the onset-rime theory of syllable
organization would result in the faster acquisition of targets. The data presented in
this chapter provides support for both theories depending on the phonological goals of
therapy. In the case of singleton consonants, the limited data of this study could not
provide evidence favoring one theory over the other. In the case of consonant clusters,
however, the remediation of /s/-clusters favored using a moraic approach, which
allowed therapy to emphasize the two consonants as separate phonemes. In
contrast, the intervention targeting /Cw/-clusters provided support for following an
onset-rime approach in therapy. In this study, encouraging the use of epenthesis by
presenting /Cw/-clusters as a /Cu/ syllable appended to the remainder of the word was
a facilitating strategy for both subjects. Unfortunately, finding support for each of the
theories being investigated does not provide independent evidence for either an onset-
rime or a moraic syllable hierarchy. From a clinical point of view, however, what
facilitated the acquisition of cluster goals was not following one or the other of the
syllabic theories. Instead, the facilitating strategy involved emphasizing that two
phonemes make up the cluster. This statement may appear to provide support for the
moraic theory, where separating the constituents of a cluster is acceptable because
cluster consonants are appended individually to the syllable node. However, when a
/Cw/-cluster is pronounced as /Cu/, a /w/ consonant occurs spontaneously as the
speaker makes the transition from /u/ to the following vowel (e.g. /ku/ + /ik/ is
produced as [kuwik]). Essentially, separating the cluster consonants by an
epenthetic vowel emphasizes the two constituents present and allows them to be
more easily produced. What appears to facilitate the acquisition of consonant
clusters, then, is emphasizing that two phonemes make up the cluster unit. The
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difference between the two theories investigated here is that the moraic theory is
better able to explain separating the cluster constituents in the case of /s/-clusters,
while onset-rime theory is better able to account for the use of epenthesis and, hence,
the separating of constituents in the acquisition of /Cw/- clusters.
A secondary question which resulted from the choice of /s/-clusters as
intervention goals in this study involved the notion of extrametricality. Recall the
earlier prediction that clusters where the initial /s/ was more sonorous than the
following consonant and, hence, was not extrametrical, were expected to be acquired
before clusters where the initial /s/ was extrametrical. The fact that both subjects
acquired /sn/ clusters first (where /s/ is not extrametrical), and that Subject 1 acquired
/sw/ before other /s/-clusters, provides support for this prediction. It should be noted
that Bernhardt (1990) reports that /sn/ was the easiest of the /s/-clusters for her
subjects to learn. Similar findings with other subjects and for other non-extrametrical
clusters (e.g. /sw/, /sm/ and /si/) are required before it can be concluded that these
combinations are actually easier to learn.
Before beginning therapy within the syllabic condition, it was asked whether
the acquisition of certain syllabic goals would generalize to other syllabic targets.
Results indicate that training the production of the clusters /sn/, /sp/, /st/ and /sk/
generalized to the acquisition of /sm/, /sw/ and /si/. Similarly, therapy focusing on
/Cw/-clusters generalized to the acquisition of /Cr/- and /Cl/-clusters. Whether this
generalization supports one or the other syllabic theory under investigation will not be
concluded here based on the rationale outlined above. An interesting question raised
here, is whether simply establishing the CCVC syllable shape (regardless of the
cluster chosen) facilitates the acquisition of all consonant clusters. In other words,
does the learning task involve the acquisition of two consecutive consonantal slots or
does it involve the acquisition of specific feature content which happens to fill
consecutive slots. The most conclusive data answering this question would be
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provided by a child who has acquired all the phonemes of English in single segment
positions but who has not yet acquired any consonant clusters. Intervention could
then focus on one type of cluster (/s/-clusters for example) while all others served as
baselines for spontaneous acquisition. The data provided by this study is
inconclusive. It can be said, however, that at the outset of the project no clusters
were evident in the twins' inventories but, by the end, all clusters were emerging
(including three-consonant clusters, as in string'). Bernhardt (1990) found that
targeting one type of consonant cluster with her singleton subjects influenced the
acquisition of other consonant clusters.
Unlike the results based on the segmental goals described in chapter 4, no
spontaneous acquisition of syllabic goals by the twin assigned to the opposite
condition occurred. Several possible explanations of this finding present themselves.
These hypotheses, however, will not be discussed here but will be outlined in detail in
the following chapter, which deals with using twins as the subjects of this study.
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CHAPTER 6
TWINS AS RESEARCH SUBJECTS
To this point, the research results have only been discussed in terms of
nonlinear phonology. The subjects' phonological deficits and progress in therapy have
been described as established or unestablished branches of feature or syllable
hierarchies. An entirely different, but equally interesting approach to the research
findings analyzes the results from the point of view of using twins as the subjects of
this project.
Twins: Handicapped or Not?
The earliest twin studies compared the development of physical and cognitive
development of twins to that of singletons. These studies concluded that while motor
milestones were reached at similar ages, twins, especially monozygotic or identical
twins, demonstrated slower development in the areas of language and social
relationships than did their singleton peers (Day, 1932; Davis, 1937; Zazzo, 1977).
Two complementary explanations account for this observed delay. First, it has been
hypothesized that twins receive much more limited linguistic input than singleton
children because the attention of the caregiver is necessarily divided (Lytton, Conway
& Sauve, 1977). Each twin has only half the amount of language directed at him and,
consequently, has only half the number of opportunities to respond verbally. While
this hypothesis may be true to some extent, the twin situation itself can account for
some of the linguistic delay observed. Matheny & Bruggemann (1972) hypothesize
that the environment in which twins are reared presents a "unique psychosocial
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condition." Since most, if not all, of their time is spent together, each member of the
twin pair acts as a language model for the other. Because of the constant interaction
between the members of the pair, twins do not use adult models as much as
singletons do. The ease of communication within the partnership resulting from
common experiences, then, may reduce the motivation to learn the adult language
system.
Several studies indicate that many of the delays exhibited by twins during the
preschool years disappear at around 5 or 6 years of age (Davis, 1937; Wilson, 1974,
1975; Malmstrom & Silva, 1986). This finding is explained by the increased
opportunity each twin member has to create his/her own experiences and friendships
with age peers in preschool and kindergarten settings. Earlier research had found that
I.Q. scores remained depressed after this age when compared with singleton scores
(Zazzo, 1960). More recent and comprehensive research in this area has not been
published.
To date, no clinical data documenting twins' progress in speech or language
therapy has been published. The current project replicated a study done by Bernhardt
(1990) with singleton subjects and, therefore, general comparisons of therapy
progress can be made. Bernhardt (1990) reports that her subjects were beginning to
acquire syllabic and segmental goals after two cycles of therapy. However, it should
be noted that Bernhardt (1990) alternated targeting segmental and syllabic goals with
her subjects. This difference in methodology may have affected acquisition time. As
outlined in the previous two chapters, the first acquisition of therapy targets by the
twin subjects of this study did not occur until three cycles of treatment were
completed. A possible explanation of this slower acquisition time (other than
attributing it to different therapy targets) would claim that the twin situation, as
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described above, continued to reinforce incorrect speech patterns because of the
continued communicative success experienced between the twins. 1 0
Heredity versus Environment
Although the earliest twin research compared twin development with that of
singletons, the majority of twin studies were concerned with determining the relative
contributions of environmental and genetic factors to development. Such studies
typically compare data from identical (monozygotic) twins with that of fraternal
(dizygotic) twins. Since monozygotic twins share the same genetic background and
the same environment, those aspects of development under genetic control will
develop at the same time. For dizygotic twins, who share only environmental factors
and not a full set of genetic ones, development might follow quite different time lines.
The general conclusion of these studies is that the language of monozygotic twins is
much more similar than that of either dizygotic twins or singletons (Mittler, 1972;
Munsinger & Douglas, 1976; Koch, 1977). This finding supports the view point that at
least some of language acquisition is controlled by genetic make-up.
The twins of the current study entered the project with almost identical
phonologies, which supports the conclusion that phonological development has a
genetic basis. The fact that these phonologies can also be influenced by the
environment is demonstrated by the project results reported here as well as countless
1 0 Research by Sonnenschein & Whitehurst (1980) found that a child's communication improves when she is paired with a poor peer communicator. It is interesting to note that Waterman & Shatz (1982) quote Sonnenschein & Whitehurst (1980) as evidence that a twin's language may improve when paired with his language delayed co-twin. The application of these research finding to the twin situation, however, is incorrect, in that twins do not experience or even recognize communication breakdown as the subjects of the quoted research did. As a result, the same motivation to improve their communication does not exist.
84
reports in the disorders literature. Language acquisition, then, is not exclusively
controlled by heredity.
Twin versus Co-twin 1 1
Relatively few researchers have followed the development of small numbers of
twin pairs on a longitudinal basis in order to qualitatively compare one twin's
development with that of the co-twin. In the area of language acquisition, one such
study analyzed and compared the grammars of two sets of identical twins and found
that one twin was in advance of the other in both cases (Bruggemann, 1970). A
qualitative analysis of the productive structures revealed that the language of the
more delayed twin formed a subset of the co-twin's syntactic inventory.
To date only four studies have qualitatively described the phonologies of twins.
The first of these, an unpublished manuscript by Edwards & Bernhardt (1973), details
the phonologies of a set of opposite sex fraternal twins. Using a phonological process
analysis, these authors conclude that the twins of their study shared an idiolect. In
other words, the same processes were acting in each twin's phonology, but surface
differences appeared because different limitations affected the application of those
processes. In effect, the more advanced twin allowed a more restricted application of
certain processes to be applied to the underlying representation, while the co-twin
allowed a more general form to be applied. The advanced twin, for example, may have
stopped fricatives in only word-initial position, while the co-twin stopped fricatives in
all word positions.
Edwards & Bernhardt's conclusions have been criticized by Ingram & Goad
(1988) because the subjects of the study were fraternal twins who, according to other
1 1 Although it is understood that the term co-twin is semantically redundant, it will be used in this thesis as an abbreviation for the phrase "the other member of the twin pair."
85
research, are no more similar than singletons in their acquisition of language. Since
other studies that qualitatively compare the phonologies of fraternal twins do not
exist, it is not possible to disclaim the findings of Edwards & Bernhardt (1973). The
existing fraternal twin studies have been large sample in nature and have only looked
at quantitative differences in phonological acquisition. Thus, it is conceivable that
such research has overlooked the possibility that one fraternal twin is in advance of
the other.
A more recent twin study by Leonard, Newhoff & Mesalam (1980) compared
the phonologies of identical twin girls and found several qualitative differences
between them. The authors concluded that the phonologies of their subjects were no
more similar than those of singletons. Ingram & Goad's (1988) criticism of this study
is based on the phone-tree method of analysis used, which they claim emphasizes
phonological differences to the point of masking any similarities. It should be noted,
however, that the findings of Leonard et al. (1980) are in agreement with the
quantitative measures of Matheny & Bruggemann (1972) who found a high degree of
phonological similarity for monozygotic male twins only. The phonologies of
monozygotic female twins were no more similar than those of dizygotic twins or
singletons.
A third twin study, an unpublished work by Ingram & Goad (1988), compared
the phonological and morpho-syntactic development of a set of monozygotic twin boys
over a five-month period. Only the phonological data will be summarized here.
Essentially, Ingram & Goad (1988) conclude that their subjects' phonologies were
remarkably similar with the single exception of the application of a word-initial voicing
rule. One twin voiced only initial /p/, while the co-twin voiced all initial stops. Despite
the authors' criticisms, Edwards & Bernhardt's analysis—that one twin's phonology
forms a subset of the co-twin's phonology-would accurately account for this data.
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A very recent study by Locke & Mather (1989) analyzed the articulation
abilities of monozygotic twins and compared the results with those of age- and sex-
matched dizygotic twins. The authors concluded that monozygotic twins were
significantly more likely than dizygotic twins to misproduce the same sounds on a
standardized articulation test. However, based on a broad analysis of errors (which
included only the categories substitution, omission and distortion), these authors
found that monozygotic twins were no more likely than singletons or dizygotic twins
to produce the same surface realization of the misproduced target. Locke & Mather
(1989) admit that a more detailed phonetic analysis of these errors is required. It is
possible that such an analysis will in fact reveal concordance between the
phonological errors of twins and indicate that one twin's phonological abilities form a
subset of the co-twin's phonology.
No studies documenting the remediation of phonologically delayed twins, other
than the present one, exist in either the twin or the speech-language pathology
literature. As such, the current research allows not only the phonological inventories
at the outset of the project to be analyzed, but also progress resulting from therapy
may be compared. As previously mentioned, the twins' phonological abilities, both
segmental and syllabic, were very similar at the beginning of the project. What is
more interesting than the initial similarities, however, is the differences between the
twins which surfaced once they began acquiring the targets of therapy.
Combining the segmental and syllabic data based on the mini probe results
presents a summary of the phonological acquisition results of the six-month therapy
portion of the project. As is well illustrated by figures 17, 18, 19 and 23 , Subject 2 not
only acquired the segmental goals of his twin's opposite condition without any direct
intervention, he acquired all the goals of therapy before Subject 1. Subject 2 began
generalizing treatment goals to novel stimuli some time after the second mini probe.
87
Except for the acquisition of /h/, Subject 1 did not show any acquisition of therapy
targets until after mini probe #4, a full four months after his brother.
The first possible explanation for why one twin should respond to therapy so
well while the other twin showed a four month delay has to do with the targets of
intervention. That is, it is possible that the syllabic goals of Subject 2 were simply
easier to acquire and therefore generalized earlier than the segmental goals of
Subject 1. This hypothesis seems especially plausible given that a requirement of the
syllabic condition was that segments be established in some word position in the
phonetic inventory. Thus, the segments themselves did not need to be learned;
instead, only the use of these segments in unfamiliar syllable shapes needed to be
acquired.
At the end of the second cycle of therapy, it was found that, while
generalization had not yet occurred, Subject 2 produced the syllabic goals regularly in
therapy and only needed cueing during conversational activities. Subject 1, however,
was having great difficulty producing the segmental targets. The target /h/ was often
produced as a voiced laryngeal fricative with much tension visible in the throat and
upper chest area, and /f/ was most often produced as a labio-dental stop with
occasional friction preceding the stop. The hypothesis that the syllabic goals were
actually easier than the segmental ones was confirmed when each twin was tested to
see if he was stimulable for the production of the other twin's targets in the opposite
condition. Subject 1 was easily able to produce /s/-clusters, while Subject 2 exhibited
the same difficulties with the segmental goals that his brother demonstrated. These
results are taken as evidence that Subject 2's syllabic goals were in fact easier
targets to acquire. As previously mentioned, Bernhardt (1990) alternated targeting
segmental and syllabic goals with her singleton subjects and found that syllabic goals
were acquired faster than segmental ones by all of her subjects. This finding would
88
agree with the results presented here and implies that syllabic targets are in fact
easier to acquire than segmental ones.
The ease of acquisition hypothesis can only be accepted as a partial
explanation of Subject 2's earlier acquisition of therapy targets. This same
explanation cannot account for the fact that Subject 2 acquired Subject l's segmental
goals without any direct intervention. Part of the explanation, therefore, must be
attributed to the differences in the twins' personalities.
Twins and Psychology
While most twin studies were primarily concerned with investigating the
nature-nurture issue, Rene Zazzo (1960, 1974, 1977) was more interested in the
differences exhibited by identical twins. He noted that in almost all monozygotic and
dizygotic twin pairs there is a dominant or leading twin. Research by Canter (1973)
indicated that identical twins reared in different environments were more similar on
several personality indices than twins who shared the same environment. In other
words, twins exhibit less similar personalities when they live together. Observations
such as these led Zazzo (1977) to the conclusion that despite sharing identical
genetic backgrounds and living in the same environment, identical twins do not share
the same psychology.
Zazzo (1977) attributes the personality differences of identical twins raised
together to the twin situation itself. He describes the main problem of this situation
as being
the conflict between the attachment to the other twin and the self-affirmation, between the resemblance that has been accepted and suffered during all childhood and the more or less sudden need for differentiation, personal autonomy, independence. (Zazzo, 1974: 347)
89
He concludes, therefore, that the twin situation leads each member of the pair to
actively search out any possible social and personality differences within the genetic
limitations set for them.
Several personality differences were exhibited by the twin subjects of this
study. The first difference refers to dominance which Zazzo (1977) claims may result
from higher birthweight, better physical condition in infancy, or may simply result from
being designated and subsequently treated as the older twin. Interestingly, the father
of the twins in this study reported that Subject 1, who was the first born and the
heavier twin at birth, was the dominant one until he was ill with a respiratory infection
for an extended period of time at the age of two. Subject 2 became the dominant twin
after this illness and was still obviously so at the time of this study. Zazzo (1977)
reports that, in the twin pairs he observed, the dominant twin generally looked after
dealing with "the outer world," while the co-twin concerned himself with the pair's
relationship. He states that in some cases the same twin looked after both
relationships. In Zazzo's (1977) terms, Subject 2 certainly looked after affairs with the
external world and probably also those of the twin pair. It is this superior social
awareness demonstrated by Subject 2 which is central in accounting for his greater
success in therapy. Increased social contact with communicators other than his co-
twin not only motivated Subject 2 to improve his phonology in order to avoid
communication break-down, but also provided him with more frequently correct speech
and language models.
The difference in progress resulting from therapy can also be accounted for from
the point of view of Subject 1. The language acquisition literature provides several
such hypotheses. First, it is possible that Subject 1 is simply a very independent
person. Such a personality would not seek out the companionship of others (beyond
his co-twin) and would not be very concerned if his language were not understood. In
this respect, an independent personality could lead to the slower acquisition of an
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adult language system. Alternatively, the phonological acquisition literature describes
some language learners as risk-takers (Macken & Ferguson, 1983). In these terms,
it could be postulated that Subject 1 did not have a risk-taking personality and,
therefore, avoided using phonological forms that were not well established in his
inventory. A third possibility, described by Wilson, Brown & Matheny (1970) in their
twin study, is that Subject 1 is less analytical in his approach to cognitive tasks. In
this case, a longer period of therapy would be required so that a greater number of
examples of the target form could be presented and attempted before the speech or
language pattern was recognized and assimilated into Subject l's phonology. Which
of the above three possibilities, or combination thereof, actually accounts for Subject
l's slower progress cannot be determined by the results of this research.
Speech and Language Therapy with Twins
Because two areas within nonlinear phonology were investigated in this study,
and because of the interest in investigating the possibility of spontaneous acquisition
of the co-twin's therapy targets, each twin was placed on different goals during the
initial two intervention blocks of this project. This arrangement necessarily meant
that the parents' support through home follow-up activities or incidental modelling and
teaching during spontaneous conversation could not be enlisted because of the
possibility of influencing the acquisition of untrained treatment goals. However,
parental support is crucial in regular speech and language remediation that does not
need to be controlled for research purposes, because it allows for "continuous" therapy
to take place.
In transferring the therapy method and design of this study to the remediation
of twins in the regular clinical setting, then, it is recommended that both twins be
placed on the same therapy goals so that not only the support of the parents can be
1 enlisted, but also so that the twins may support each other's progress by
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demonstrating the accurate production of targets. Given the cited research findings,
as well as the results of this study, it is quite possible that one twin will acquire the
therapy goals more rapidly than the co-twin. Using a cyclic approach, as was done in
this study, may allow for the same goals to be targeted despite an unequal acquisition
rate.
The design of the current research project required the subjects to be seen
separately for therapy. If, as is recommended above, both twins were placed on the
same goals, one needs to ask if it would be beneficial for them to be seen at the same
time for therapy. This question was investigated during the fifth and sixth treatment
sessions of Block 3 when the twins were seen together for therapy. When the twins
were together, the dominance relationship was emphasized to the point where
Subject 2 completed all the activities for both himself and his brother. During this
time, Subject 1 appeared to withdraw from the therapy situation, allowing his brother
do all the work and "deal with the outside world." This withdrawal even extended to
activities that did not involve language activities and, therefore, rules out the
hypothesis that Subject 1 felt inhibited because of the feeling that he may be
linguistically inferior to his brother. Whether Subject 2 was seen for therapy together
with his brother or on his own made no difference to him. For Subject 1, the less
aggressive of the pair, attending therapy with his twin, however, did not lead to
productive and active therapy.
Given the above findings, it is recommended that twins be seen separately for
therapy, so that the less dominant twin has equal opportunity to interact with the
clinician and to benefit from language stimulation. It should be noted, however, that
some anecdotal reports from parents and teachers indicates that twins constantly
monitor the well-being of the co-twin. Separating twins, therefore, such as placing
them in different classes may interfere with this monitoring and lead to anxiety. It is
appropriate to place twins in the same class during the preschool and early elementary
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school years if a strong relationship is demonstrated. Separating twins for short
periods of time, however, as was done during the project, should not be an anxiety
provoking situation, especially if the same activities are being completed because the
same therapy goals are being targeted. In this case, the first twin to attend therapy
can be reassured that the co-twin will complete the same activity. Likewise, the
second child can be told that his/her sibling just completed the same tasks. In this
way, each twin has a good idea of what the sibling is doing during the time that they
are separated.
Autonomous Language
No study of the language of twins is complete without at least a fleeting
reference to the existence or nonexistence of autonomous language. Also termed twin
language or cryptophasia, autonomous language refers to a "secret language" which
some researchers claim exists between twins (Zazzo, 1960; Luria & Yudovich, 1968).
Even if a secret language does not exist between twins, not all of the language they
direct to each other may be intelligible to those outside the twin situation. Where
phonology is concerned, unintelligibility can result from protracted phonological
development, as was demonstrated by the subjects of this study. Because their
phonologies are developing at approximately the same rate, each twin is able to
understand the utterances of the co-twin even if nonstandard forms unintelligible to
outsiders are used. In the case of the subjects of this study, the highly productive
form [kaku] continued to be used for thank-you well after superior phonological skills
had been acquired. Although this utterance may be uninterpretable for many, it
presented no problems within the twin pair. Such "regressive phonological idioms"
have also been exhibited by singletons on a normal developmental timetable (see, e.g.
Ferguson & Farwell, 1975).
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To date no researchers have reported the use of novel syntactic forms—that is,
forms that are completely idiosyncratic in grammatical structure—by members of a twin
pair. Idiosyncratic forms, however, have been observed in the secret language of non-
twin siblings (Diehl & Kolodzey, 1981). With regard to twins, several studies have
observed the use incomplete utterances, shorter utterances and a greater number of
emotionally toned phrases when communicating (e.g. Savic & Jocic, 1973; Zazzo,
1977). Zazzo (1977) postulates that the linguistic deficit he observed in his twin
subjects is compensated for by an increased development of other nonverbal
communicative functions. Richon & Plee's (1976) finding that twins generally score
higher on the nonverbal tasks of an intelligence test supports Zazzo's (1977)
hypothesis.
This author questioned an adult identical twin about her feelings regarding the
existence of a secret language between herself and her co-twin. She reported that it
was not a secret language that existed between them, but rather a deeper emotional
bond than she experiences with others very close to her. This emotional
understanding of each other allows each twin to gain the intent of a phrase even when
it is incompletely or inexplicitly stated. To someone outside the twin pair, however, it
may appear that a secret language exists. The connected utterances of the subjects of
this study have not been analyzed to see if shorter or incomplete phrases were used.
That a deep emotional bond existed between the subjects, however, cannot be
disputed.
Summary and Conclusions
This chapter re-interpreted the findings of this phonological study taking the
atypical subjects into account. Twins are considered to be atypical in that they create
a unique environment for each other by sharing all experiences and by mirroring each
other's development.
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The subjects of this study entered the project with essentially identical
phonological inventories. This observation is in agreement with the twin research
literature, which reports that monozygotic twins tend to be more similar than dizygotic
twins or singleton children. This similarity in language acquisition is generally
accepted as evidence that at least part of language development is under genetic
control.
Qualitative analyses of the language development of monozygotic twins have
shown that, while both twins will follow the same path to acquisition, qualitative
differences may be apparent at any one time. For example, similar branches of the
phonological hierarchy may be emerging, but their specific acquisition time may differ
between twins. This relative acquisition time was the most obvious difference
between the twin subjects of this study. Subject 2 began generalizing multiple
therapy goals during the third cycle of therapy. His brother, however, required a
further three cycles of treatment before a similar acquisition spurt was observed. Two
hypotheses were cited as possibly accounting for this observed difference in therapy
progress. Initial investigation led to the hypothesis that Subject 2's syllabic goals
were easier to acquire than Subject l's segmental goals. This hypothesis requires
further investigation—possibly through comparing the results of intervention with
another twin pair where the dominant twin is placed on segmental goals (but see
Bernhardt, 1990). The second hypothesis accounting for the therapy results is based
on the social awareness of the twins. Subject 2 was found to be the dominant twin of
the pair and, as such, demonstrated superior social skills and awareness. This social
awareness emphasized situations where communication breakdown occurred and
motivated Subject 2 to acquire the phonological targets of therapy. Increased
awareness also drew Subject 2's attention to correctly modelled target forms. It was
suggested that Subject 1 was either not a risk-taking language learner or was not
analytical in his approach to cognitive tasks. It seems unlikely, however, that
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monozygotic twins would employ different cognitive strategies. Researchers have
claimed that the personality differences (rather than cognitive ones) between
monozygotic twins develop from the need to distinguish themselves as individuals
separate from the twin situation. The difference in therapy progress observed in this
study is more convincingly explained by the latter hypothesis.
Based on the method and design of the current intervention project,
recommendations were made to place twins on the same speech or language goals in
therapy so that follow-up home activities can be completed with the caregivers. In
addition, it was recommended that twins be seen individually for therapy so that the
dominant twin does not complete all the activities and provide all the language while
the co-twin withdraws from the tasks.
Finally, an evaluation regarding the possible existence of autonomous
language for this twin pair was given. Essentially, the unintelligibility of these twins
resulted only from delayed phonological development. This delay may mean that
persons outside of the twin couple will not understand what is said, while the co-twin
has no difficulty comprehending the utterance because their phonological inventories
are essentially the same. At least some of the inexplicit language which has been
observed between twins is attributed to the fact that a deeper emotional bond exists
between the pair allowing less detail to be verbalized before the intent of the
utterance is conveyed. The current study focussed only on phonological acquisition
and did not investigate this latter area.
It can be concluded that twins are unique subjects for research projects which
investigate not only issues concerning heredity in language development, but also the
personality and social factors that influence language acquisition.
96
CHAPTER 7
CONCLUSIONS
The main purpose of this research was to investigate the possibility and
advantages of applying a nonlinear phonological theory to the assessment and
remediation of phonological disorders. Researchers have recently been developing
nonlinear theories to account for the phonological rules and operations observed in
different languages. They have found that, where previous generative theories have
required rules involving complex transformations, nonlinear phonological principles
allow rules to be more simply stated and logically related to similar rules in other
languages. Similarly, linguists interested in child language acquisition have
discovered that when acquisition data is examined from the point of view of nonlinear
phonology, the data no longer appears to be deviant or idiosyncratic, but instead,
follows the general principles and rules governing all languages.
To date only the recently completed project by Bernhardt (1990) and this
research have investigated the possibility of applying nonlinear principles when
assessing and determining goals for phonological remediation in the speech-language
pathology clinic. Following the research design and methodology of Bernhardt (1990),
the current project applied nonlinear principles to a six-month phonological
intervention study with a set of identical male twins. An assessment of the twins'
phonological abilities at the outset of the project revealed that their strengths and
deficits could easily be described as "established" and "unestablished" branches of
nonlinear hierarchies at both the segmental and syllabic levels. Although these two
97
levels are associated in nonlinear theory, they were separated in this project to create
a segmental and a syllabic condition for investigation.
The segmental portion of the current research compared the acquisition of
"higher" nodes of the feature hierarchy with "lower," or more deeply embedded
nodes. The hypothesis that higher nodes would be established more quickly than
lower nodes was investigated by targeting pairs of segments whose salient features
fall at different levels in the hierarchy, within the same cycle of therapy. Intervention
at the segmental level allowed the acquisition of two pairs of features to be compared.
In both cases, the segment, whose salient feature was higher in the hierarchy, was
acquired first. Bernhardt (1990) reports similar findings for her singleton subjects.
These results, then, support assessing, and subsequently determining goals for
intervention, based on nonlinear feature hierarchies. Conversely, it can be concluded
that the results of therapy with phonologically delayed subjects provide independent
evidence supporting feature geometries.
Within the syllabic condition, it was not possible to compare the acquisition of
higher level branching with the acquisition of more embedded branching as was done
in the segmental condition. Therefore, remediation activities within this condition
contrasted two different prosodic theories—the moraic theory and the onset-rime
theory—to ascertain whether acquisition results could provide support favouring one or
the other theory. The majority of intervention within this condition targeted the
production of various consonant clusters. The differences between the two syllable
theories affected the presentation and stimulation activities of intervention.
Intervention following moraic principles allowed clusters to be presented as separate
segments, while intervention based on onset-rime principles presented clusters as a
unit. Depending on the clusters targeted, support for both hierarchies was provided by
the results. Separating the consonants of a cluster to emphasize the presence of two
constituents facilitated acquisition for the subjects of this study. The moraic theory of
98
syllable organization better accounts for this approach, because onset segments are
appended individually to the syllable node rather than first being grouped under an
onset node in opposition to the rime. The onset-rime theory, however, is better able
to account for the intermediate acquisition step of epenthesis, which is commonly used
by language learners.
A comparison of the results of the two conditions of this study revealed that
the syllabic targets were more quickly acquired than the segmental ones. Trial
stimulation of each twin on the co-twin's targets supported the conclusion that
syllabic targets are in fact easier to acquire than segmental ones. The results of
Bernhardt (1990) agree with these findings.
Comparison of Nonlinear Phonology and Phonological Process Theory for Phonological Intervention
Outlining the advantages of nonlinear phonology requires that this theory be
compared to other phonological theory options. Currently, the most popular method of
analyzing phonological data in the clinic uses a process analysis approach. Stampe
(1969), who first organized phonological data according to processes, claimed that
these processes represented mental operations and were unordered in their
application to the (assumedly) adultlike underlying representation. Researchers
currently using a phonological process framework hesitate to make claims regarding
the status of the underlying representation. Not enough is known about the language
learner's perceptual mechanism to conclude that the underlying representation is
adultlike. This being the case, then, it is difficult to claim that phonological processes
provide more than simply a description of the language learner's surface production.
The first advantage of nonlinear phonological theories over process theories
lies in the theoretical claims made. Nonlinear theory argues that the hierarchies which
are basic to every level of phonological organization reflect the mental representation
99
of speakers. As such, nonlinear phonology provides an explanation of phonological
rules rather than just a description of them. When applied to language acquisition,
phonological processes necessarily imply that children are avoiding certain segments
or syllable shapes ('fronting', for example, implies that the language learner is
avoiding a "more back" target than her surface realization). In contrast, nonlinear
theory claims that any discrepancies occurring between the child's surface forms and
the adult targets result from the child not yet having established certain branches of
the feature or syllable hierarchies.
The second advantage of using nonlinear theories over phonological processes
becomes apparent when determining targets for remediation in the speech-language
pathology clinic. Since phonological processes are unordered, according to Stampe
(1969), the theory itself provides no guidelines regarding which processes should be
targeted first in therapy. Clinicians currently base decisions regarding intervention
goals on suggestions such as following the developmental pattern of typical language
learners in eliminating processes, or targeting those processes which are most
detrimental to the intelligibility of the child. Remediation according to nonlinear
principles involves establishing the higher, or less embedded, branches of the
hierarchy before establishing the lower ones. The language learner necessarily moves
from acquiring the most basic (and also universal) branching to the more complex
language-specific system.
The strongest argument in favor of using nonlinear theories in the clinical
setting would result from remediation based on nonlinear phonological principles
leading to the faster acquisition of therapy targets than if goals were chosen based on
targeting phonological processes. Such a finding would imply that nonlinear
hierarchies provide a closer match than phonological processes with the language
learner's mental representation. The scope of this intervention study could not
incorporate a comparison of these two theories. Further research is required that
100
compares the acquisition of phonological targets in intervention based on following the
principles of nonlinear phonology with the acquisition results of remediation based on
phonological process analyses.
Limitations of the Study
The main limitation of the current project is that only two subjects were used.
Since two conditions were tested in the intervention portion of the research, each
condition could only be tested on a single subject. Claims based on the results of only
one subject are not convincing evidence. The findings of this project, however, agree
with the results of intervention with six singleton subjects (Bernhardt, 1990). Results
from the eight subjects, taken together, demonstrate that nonlinear phonological
theories may be applied to the assessment and remediation of phonologically delayed
children. Further research applying nonlinear principles in the speech-language
pathology clinic is required to further substantiate this claim and to add to the body of
"nonlinear phonological remediation" data.
A second limitation results from having used twins as subjects for this
research. Chapter 6 outlined the complex interrelationship between the members of a
twin pair. The psychological factors entering into this twin relationship are difficult to
tease apart, meaning that research findings can only be tentatively generalized to the
clinical population as a whole. The comparison of rates of acquisition with the
personality differences of the twin subjects of this study led to the general claim that
social awareness is prerequisite to phonological acquisition. This claim must be made
with caution, because the two conditions of this study were unequal in difficulty. The
findings may have been different had the opposite twin been assigned to each
condition. A repetition of this study assigning the dominant twin to the segmental
condition is required in order to substantiate any claims made regarding the role of
personality factors in phonological acquisition.
101
Since nonlinear theory is currently motivating a great deal of research and is
undergoing rapid development, changes in feature and prosodic hierarchies may lead to
more refined clinical decisions regarding treatment goals.
The main conclusion of this study, then, is that nonlinear phonological theory
provides a workable and coherent framework for phonological assessment and
intervention. Based on the positive results discussed here, it is claimed that
intervention following nonlinear principles presents independent evidence supporting
this theory. And finally, it is concluded that nonlinear theory provides a better
theoretical framework than phonological process theory because of the explanatory
value of nonlinear hierarchies and the logical process of choosing targets for treatment.
102
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108
APPENDIX 1
NONLINEAR MINIMAL SPECIFICATIONS OF ENGLISH CONSONANTS
109
APPENDIX 1
Nonlinear minimal specifications of English consonants:
Abbreviations: [cons] = [consonantal] [son] = [sonorant] [+cont] = [+continuant] [*cont] = complex continuant marking required for affricates [-ant] = [-anterior] [dist] = [distributed] L N = L A R Y N G E A L NODE
/m/ ROOT [cons] [nasal]
P L A C E /
labial
ROOT ROOT [cons]
PLACE /
labial [voice]
[cons]
P L A C E
labial
/n/ ROOT [cons] [nasal]
ROOT /d / ROOT [cons] [cons]
L N
[voice]
ROOT [cons] [nasal]
P L A C E
dorsal
fkj ROOT ROOT •[cons]
P L A C E
I dorsal
[voice]
[cons]
P L A C E
dorsal
110
HI ROOT [cons]
/ M+cont] P L A C E
labial
M ROOT
L N
[voice] P L A C E
labial
-[cons] [+cont]
Isl ROOT \ M c o n s ]
^ [+cont]
ROOT
L N [cons] [+cont]
ROOT
L N [cons] [+cont]
[voice]
III ROOT \ M c o n s ]
^ [+cont] P L A C E
/ coronal
1 [-ant]
Izl ROOT
^ 7 V [ c o n s i L N j x[+cont]
/ P L A C E [voice] |
coronal
I [-ant]
IBI ROOT P\Mcons] j \[+cont]
P L A C E
coronal I
[dist]
Ml ROOT [cons] [*cont]
P L A C E
coronal
I [-ant]
/d3/ ROOT
L N
[voice] P L A C E
coronal
I [-ant]
[cons] [*cont]
ROOT
L N P L A C E
[cons] [+cont]
[voice] coronal
I [dist]
I l l
/w/ ROOT 1)1 ROOT r^[son] ^-[son]
P L A C E
I labial
N ROOT /r/ ROOT [cons] J\"-[cons] [son] j ^[son]
P L A C E
I coronal
I [dist]
APPENDIX 2
GRAND PROBE WORD LIST
APPENDIX 2
Grand Probe word list (based on Bernhardt, 1990):
Vowel-initial: /nV M ivi
airplane mask basket page all me bee pages ear milk bib pie eat mom black Pig eating mommy blue piggy egg money boot plum eyes mouth boots pour ice mouthy bootie pouring icecubes music brown present icy musicbox brush pup itch brushing ' purple itchy buzz off buzzing A /
SJll orange A V /d/ television up toe
nine dad toot /s/ no daddy tooth
noise doll , toothbrush Santa Claus noisy dollhouse toothy scarf dolly truck screwdriver dress tub see dressing tubby sewing machine T.V. sis glasses M sleep glove Ata/ sleeping glovey cage smooth go cagey " G " snake green candle judge snakey gum clock jump snow gummy coffee jumping snowing comb soap /s/ (cont.) combing A ; / spoon string cook spring sun cooking chair squirrel sunglasses crayons cherries star sunny key chicken starry sweater quarter church
HI NI
feather van fingers fish fishing five yellow flower frog
M N
rabbit la radio laugh read laughing reading leaf red leafy roar Lyle row rub rubbing
Ihl M
hang zipper hanger zoo hi horse III hug hugging shoes
shirt
/w/ / e /
wagon three watch throw watching throwing wave thumb waving why m
that
APPENDIX 3
GRAND PROBE D A T A FOR BOTH SUBJECTS
116
APPENDIX 3
Grand probe data for Subject 1:
Target $.™dJ*9teJ± lGrandProbe#2 J G r a n d Probe #3 JGrand Probe#4
/vowel . i n i t i a l / j j j . j
airplane i 3 r P e ' n ^ 9 r P? i n i E rP5 i n :?TP e i n
all j i ! jaco
ear jer j j jir
ears | lirs
eat _ _ jit
eating ;i?irj
?gg |eg | |eg jefl
?gg? | [eg? | |
eyes ?2U)n.ts jais jaiz jaiz
ice jeis ! i j
icecubes j a i k j u b s i j
icy jajsi | _ j j
itch jus j jits)
itchy iitsi i :its)i ii?s}i
off ias jas jas jas
ZIZZZZZZZZZ^ZZZZZZZZZZZZZ^ on ian Ian i
j i [(pra^ges! I orange i P l i n t s i p r a n t s w i o r e n t s e z j 5 ™ i L .
j j-?™t?. i |
ffi | I b p hs.
elephant j ; JAjahat jaeamant
I n i t i a l / p / j j i j
page j p e ^ s j p e r d z j p e i d s . J E ^ d s | j j jpeids)
pages jpe(fx)a j jpeidaaz jpeidza
117
pie
P»g..
p»ggy. m\..
ipai
JPM.. M9...
M9L
M9...
plum iP.Am .•P m..
jpor...
.|PAm..
jpor... pour jpor
jppnrj
jpor
r^unng .mm jp?ng j presents jpej3?ts present. !Pe?.n. . Ipefiant
[P"P JR*R I
P.urp.1?.. jparpol jparpol
pitcher ]P">?.r... jptfsar
Initial Ibi
basket
bee
jbsskit
Ibi
jbjesnkEt
I b i '
ibsskit
ibi
bumble bee
bib
jbAmbAmbi
jbib
jbAmbAbi
jbib
black
boot
jbsek
ibut
;ba?k ibaek jbaek
Ibut jbut
ibuts boots
boo tie
ibuts
ibudi
ibuts i(booties) Ibudis
brush ibAS ibAS \b\J ibAS
b n j s h i n g i ^ S " ] i sn) $/±[}J}.. jbASirj
buzz
buzzing
ibAS
jpA(s)iig
ibAS ibAds
jbj\dsnj
jbAds
ibAzPirj
blue ibu ibu ibu
118
b r o w n I IbEeon I ibaon
box jtKits jbats j jbaks
In i t^ /m/ j j j j
mask :m..?.?.H. imaesk
m e i m i i I
milk 1 ™ . ! ® : ^ . i m ? © H . Imeok Imiak
mom imam
mommy imAmi
money imAni
mouth im.A<?? imaos j imaof
mouthy jroaosi imaofi
m u s i c b o x U u ? ? n b a t s :
music jniusik |musek im.uj?i[K imuzik
initial/)/ j [ [ ]
television l. j.?!?.?!?!}. Il j.?. .??11.. Jtejabmdsan jtejabmdson
TV j t i j i j t i j i j t i j i j t i j i
toe itoo i j
tooth I t u s I itus ituf
t o o t h y j t u s i j j t u t i j t i i f i
toothbrushJ&USOAS i t o s b A S j t u p A S j t u s h A _ Q
teeth itis itis jtis
truck jtxAk |uk itak itak
j [ itAk j
tub jtAba jtAb j j
tubby jtAbi ! i I
119
Initial /<V j ; j
dad jdaed I
d a d d y j d s d i . [ !
doll idaa jdaea
dolly idaji idadi idai Jdaji
doUhouse ;< U?o(s) [ i °:haos [daohaos
dress j d e s i d e s ides jduwes
.dressing jdesnj I jduwesd
Initial /n/ ] | _ i j
nine inain j jnam
no !n.?5L..: ! n o \noo
noise \ [noiz I
noisy inoisi inoisi !
initi^Jk/ j j j j
cage j k e i s j k e i s [ k e c d s jkeids
cagey j k e i z i I ikeidzi ikeulzi
candle kxnoo i k s n d o G ) i k s n d o Q [kacndoo
clock jkak jkak jkak jkak
coffee I!?.?.?.;?. jkasi jkasi jkafi ikasiPi [ j j
comb j k p m j k p m j j k o m
combing . jtomnj jkomirj j ikomirj
cook jkok ikok j \
cooking jkoknj i I j
crayons ikeijans ikerjanz j ikeijans
120
I i i ikjeijanz key j k i j k i I j
quarter ikprdajr ikordsr ikordar ikorda
catch jkaets I jkae?s)> ;ks?s
catcher | | jkaetsar m?Jff3.r
Initisd /g/ j j I I
glasses igeaeses i9<?sez iS?.??83 \ $ £ ? S Q Z
j J S ? ? ? 8 ? 8 j g ? . ? ? 8 3 8 J9??83.z
glove ig/\h jgas jgA<j> jg/vf)
gloyey jgAsi j I IgAyi
go jgoo jgo j jgoo
green jgin [gin J9™in j ! I |9?win
gum i g A m i g A m j igAm
gummy jcpA.mi | J9*mi..
feather |P.aij?r j p a i j a r l § A . S 3 r . j f e y 3 r .
fingers !P m 9 3 r s : P ^ 9 3 r 8 i P 3 9 3 r z . i l ^ Q S 3 ! ? . .
fish ipes jpes jBis) jfjs
fishing ipesn] j j P e 8 ? n | P ^ S . ? ? 1
five ipais jpai j 6 f a i s j f a i s I !(0Pw.ers) j j
flower i R ? . 9 . W 3 r . ; P a * ? . w 3 r . s . j . ( ? . ? w . ? ] L
&pg |pqg |pag. pa. jM...
four jpor | j 6 f o r i f 3 ! . . . .
Initial /y/ j | : [ ]
van ibaen ibeen ivaen
121
j I [bysn i
vest j | ibvest Ivest
j j [byest j
voice jbais iypis
InitM./s/ | j | j
Santa Claus j^ntekas tontakaa i t a n t a k a s i i ^ n t e k a s
scarf j k a r s j k a r s [kars jkarf j ! i ikars
screwdriver j k u d a i ( P ) 3 r i K u d a i ^ o r ikudaisar ikiudjisar
see :ti ;ti ]
??wing.m^?h.ll?e. j ! 3w i3 m .? t i n . j t ew in t in l!?.9.w„m!5?.?§?.5 l wfflrflsstin. j | j t o ^ m m a s t i n ]
sis jtes i [ itis
sleep j t i p I j t i p j t i p
sleeping j t i p i r j I t i p i r j i t i p i r j j t i p n j
smooth jmus i i f M @ M U X Y ) . i | | iSm3 mu(y> j j i jsmuz
snake ineik ineik isneik isneik
snakey ;ne?ki \ \ j
snow jnoo jnoo J s n P 9 ;Sn.?o
snowing i ! P w m i n o c D t r j |sno°wn] Isnowrn
soap itoob jtoop itoop js-top
spoon i p u n i p u n i p u n i s p u n j | ipun..
spnng. jprn. jpfpm jpfnj. ipea I I I
squirrel jkarl jkorol ikaral ikar-skarel
122
star
starry
string
sun
itqr
item
iun
itar
M .
itar jstar
istari
itarwrr]
iun
sunny
sunglasses.
jtAm
jtAngjaJtES
itAni jtAni
jtAnc^Wdz
iwedar
iUni
junga!(8)oz
sweater
skirt
iwedar
Ikart
jswedar
Iskart
i(snack) Isnask
j(staple) jsterpol
j((spanking) isperjlQ
Initial /z/
zipper ihepar i?p?r. i?ipar [sPipsr
j?ipor
zoo ..........
idu idu itzu
three
throw
jPL ifi
jpa?:foQ.
jfowrrj
ippa. .jP3!?... [poo
throwing
thumb
jppwn]
jtAm
jppowrn
itAm
ippowirj
jtAm
/07
that idAt idA?
HI.
shoes
shirt
i(shoe) jtu
itart
itus
itart
ituz jtuz
itart
123
I I [(shake) i shaking j | iteik jsteSnj
show itoo itoo
chair Itesr iter iter Iter
[ ( c h e r r y ) j j [ cherries ithcen?i jteriz iteris iteriz
chicken juksn jnkan itikan jtiksn
church itarts [ t e r t s [ ! f 3 r ! f [ t 3 r J f .
m ; | ; ;
ZllZIIIZiZIIIIIZ judge jdA3S idAdJ jdAdJ" jdAds/:
ZZ^ZZ^ZZJZZZZZZZZZZZZZZZZU^^^ i I feps) j^mps)
jump idAmp jdAmps [j^mps...
jumping idAjrnpir[ i^njpni •<^m.P.m. Lf^M??].
j(iet). idet
Initial /h/
hang pen, Ijsn m jhan
hanger [jensr [ j < ? r j 9 r i h a e r j a r [hangar
hi [jai i?ai [hat [hai
horse [jors [jars i h p r s ; h ? r s . . .
h u g m I I j hugging pAgin | [JAgin j
hands [ [ [hsndz I
hops [japs [haps [haps..
j | ( h e n ) [ |
124
hens | ifien ihenz jhenz
house j j a p s i j a p s i h a p s j
I n i t M / j / I j j . j
yellow J e J ] p © D e . ? P ^ ! U?]?!?® ijedbo i | \
Initial_/w/_ j : I i
wagon iw.£9 3 r! iW E9 3 n. i w . ? 9 3 n . i . w a ? 9 3 n
watching jwatsirj jwatsig jwatsiij jwatsnj
wave jbeij I \we.iQ !
waving jPetirj [ w ? ? . ™ ! I
why iwai iwai ; iwai
InmaJ /!/ i i I I
la ja IdA ilJA
laugh i j a e s I p a e s i j a e s f
i i i i m laughing i j < ? s n ] i J esni 19$$%}.
leaf [jus |jis [jis ijif
leafy jijJi I j j i s f i i j i f i
Lyle jjaijo I [janpo jjajo
I n i t i a l / r / j j i j
rabbit jw^bit i w ? P . ! t I * ? ! ? . ? . J T ^ M
radio iweidoo IweideiD .Jwi^d?Jp„9 Lw^d£?.9.
read jwid j wid i . i
reading jwiniri i}^M?m iwundnj
red jwed jwed iwed
125
roar iwor iwoar iwor
row IWDQ iwow
rub jWAb jWAb JWAb
rubbing iwAbin iwAbin iwAbm
Grand probe data for Subject 2: Target ^Grand. Probe*1iGrand.Probe #2 iGrand[.Pjrobe:#3iG^andPjrobe #4
/vowel initial/ } [ \ [ airplane i e rJ? e m • e rJ? e m ^ e n? e i n i e r i ? e m
ear lir jir jir
ears jirs jirz
eat lit
eating ji?in
litin
egg. m m ;eg m
eggs jeids [ I !
eyes ja^s jars jarz iaiz
ice | I j jais
icecubes | I i iaisl^ubz
icy j j I iaisi
itch jits [ j [
itchy j i t s i j i t s ^ i jitsi |
off j o s s j a s l a s jaf
on }an ian Ian I
orange l?. m^ i5!™s. !? ?.n. 1?™.??.
up JAp jAp j [Ap
elephant . } \ l^sm?"!;!?$i3i? n.t.
Initial/p/ | I j j
page i_pei ] P ? . ! S . ) . I p e i d s [P5?ds) jpeis j p e i s | |
127
Pag?.?... jpeisdas I JB . ).?.Z... jpeidzaz
Pi?.. jpo?..
PJ!g.. ma.. .Ma..
jpigi.
.]p&g..
.jpigi.. piggy.. mai
plum ]PA m...
:por
present iPAJ.3n.t I {(presents) [ ipcujant j s p a i j a n t s | f A . n . ? . n . L
ipASsnt I ipajj3.0*?... jspajant
iPMPPJes).. jpApis Pffi. JPAP...
purple JparppJ
jperpars
iPprpsl. jparpaj
papers ipep.3r.s.
pictures ipitears jP!?l?rs.
jpitsar pitcher
Initial /b/
basket
bee
bsskit
bi
Jba^kit
ibi
je^bseekat
Ibi ibi
ibAmbalbi bumble bee ibAmbalbi ibAmbalbi
bib
black
big
ibaek ibsek [bsk ibalffik
jbuts
i(bj)oties) jbudiz
ibAS
boot
boots
bootie
brush
but*
puts
budi
DAS
[but
jbuts
IDAS
{but
ibAS jDAS)
128
brushing B?A.S.P1 jbAS.?l [DASIIJ ibASirj
buzz jbAds itwjs i b A d s i t y \ d s
b u z z i n g l b A . s n j 1 jbA?m l P A Z m
blue } i b u a i b i r a i b a l u
b r o w n \ Ibaeon i b j e o n I ! ? ? ! 3 ® 0
| [ I ipaon
breakfast jbatsiast Ibatsiast j J I ™ I I [ ( b a t h t u b )
bath jbjeas | I jbaestAb
tenchii jbEntS/t ibens
Initial/m/ j j j i
mask in^sk j if?.?^
me jmi i i j
milk ™i?H imiok imeak
mom jmam j i
mommy; jmorni imAmi [
m.9.nev. jmbAni
mouth irn.A9.s. i m a ° s . i"!?.?8 i m a ® °
mouthy i m A ? s i i imaosi [macaGi
musicbqxjmusitbats | I i
music irnusik im uS!k imusik imusek
Initiai/^ { j ; i
television itajabizn . itedabindsan itedayizan
TV jtiji. i t y j i t i s i itiyi
toe |too { | j
tooth itus I I i
129
t o o t h y j t u s i [ j
toothbrush jjusbAS i l u s b A S [ t u s o b u s [ t u s b A S
teeth j t i s | I itif
ttuck ItAk [uk itak jtwuk ituwAk ituwAk
tub itAb ItAb
tubby JLvbi
Initial /d/
dad idxd
daddy Maedi jdaedi idsdi
doll Idas Ida© Ida
dolly j d a d i i d a d i jdani idadi
tollhousei^aos j i d a o h a o s idjadihaos
dress Idas ides ides idawes
dressing idesi
Initial /n/
nine inain
no inoo ino inoo inoo
noise inois
noisy in3!!?i I inoisi
nose inoos inoos inooz
Initial /k/
cage j Gis). i.keis ikeiz ikeif i ikeids
cagey IH^?.! i ikeidei jkeidzi
130
candle iksnoon iksendca ikaandca Ikandoo
clock !kath ikak ikak
coffee ikasi ikasi ikasi ikafi
comb Ikom [kom ikom
combing j k o m n ] j k o m i i j i |k?.mirj
cook ikeok ikak
cooking jkoknj
crayons ikeijans ikeijans jkuweijanz Ikaweijanz
key jki iki iki
quarter iH?.?^3^ ikprdar ikw?.rd?r. [kwPJd3r.
commercial ikamarsoo ikamarsal
catch [ iksetf
catcher j I i k s e j j a r
Initial /g/ } i i i
glasses jga^ses J9?832. | e e si s igjaesiz j I igeaesps I
glove IQA?:^ igAp igAB igAb
glpyey i g A b i [ i i g A b i
go jgoo jgoo i igo©
green igin igin jgswin jgwin
gum igAm igAm igAm igAm
gummy JM™.! 1 I [gAmi
feather JPA.U?![ JESli.3! [ P . 3 * . ? 3 ! ? i ? 3 2 3 ? . . . .
fingers iPJ&]93rs iPPig31"2 i^ng.3!2 i?m93r?.
131
fish jpis ipis ipis ifis
fishing jpisnj jpe?)"] ! P ! s n l W j J H
five jpais j i6ais jfary
{ i(flowers)KOpw???) [ flower iPSow?! [sfaowsrz [faow??!
fr°g k»a jpqa |spqg fe>g
jiTeet) j !(ClnJshedj. [(foot) j p i t s { [Bnust jfot
InitisLl /y/ | | | I
van rpaen i ibsen ibaen | j ' j iyan | [ i iyaen
vest { I jbest jvest
voice j \ jbvois ibois
Initml /s/ | I | |
Santa. Claus j t e t e k a s | t o t o k a s itantakaz Itotoka v) { j t a t a k a s : iMtakaz
scarf ikar? ikars ikars iskarf
s.c.Je.y,!. rl.Ye.r. IHyMajspr. iHu.daisar iKu.sdaiS3r [Hysdaisar j I j t o s j ^ a i s a r [
see i t i i t i iti [si
sewing machine {teommastin [toointin itpwnpiatin itownjmatin I itpwnjdatin i i
sis josts j i id ist
sleep {tip | jstip istip
sleeping itipm i t i p m [ s u p n j [tipirj
smooth ir?.1??. j ismuz $33®.
snake in£?k. isneik ;sJM?k is-neik
132
snakey jneiki
inoo
jneiki
inoo
jsneiki
isnoo snow isnoo
snowing i n ? . o m i n ? . o m i s n o w i T j jtoop Up>c>p>
spoon j p u n { p u n j p u n
isnownj
isoop
ispun
soap
[spun spnng. j(5njkor
M?fc ..!w.e.D...
jspn).. i$BSL
s q u i r r e l j k a r l ikaral iskorol iskarol
j(stars); jstarz
i(stars) star :tar
itari
;tar jstarz istari starry itari
koirj smng itAn
jtuwrn.„
isun
ituwirj
sun sunny sungiasses
jtAni ItAni iUni itAm i t e p n g f f i o s e s i itAngaesi iKAngassiz
jiAngaesis js-tuwedor
]Ungassiz jswedor sweater
slippers
}tAdor
jtipars ioparz iuporz iskart skirt ikart
stereo Initial /z/
itenoo istenoo
zipper 1?!P?L j?'P.3r.
zoo
wz. three
idu
iPi
iPiTipor jsPipor
WZ1 izu
61
•zrpor
:zu
133
throw [ p o o [ p o o [ p o o [ 0 o o
throwing ]P?.onJ [P?.?w.rn iC 3 0 .^* 0 .
thumb ItAm ItAm ist\m ium
that jdset idaet
OL
shoes itus j t u s I [tuz
shirt j t s a r t [ t o r t [ s t a r t i t a r t shaking [ [ jsteikni [tmkm show | I J s ) a o [ t o o
{ | [sjoo [
chair j t s e r i t e r ister I
c j h e j r r i . e s i t f e r j s [teri?. ideris Iseriz ! \ [ i^eriz
chickens i?.?.?n.s i ^ 3 n z . [u^302. fr^n.2. church [ t a r t s j t s r t s jtartf
nzzizzzXzzzzzzzi^^ zzzzzzzzzzzzzzzz^ judge idMJs. j d ^ d s [ d A d f [ d A d s )
[ [ [ Q u m p s ) [ ( j u m p s ) . , j u m p l ^ A m p i d A . r n p . J d ) A r n P . s . [ d j A r n p s jumping [d mpS)..! jdj\nipin [d3A mprn[dSArnprrj
[ ] [(juice) [(jet) [ [ [dus [dget
| [ [ [(Jacket) i i [ [daskat
134
Initi^/h/ ] ] | | hang j j e r j j j e e r j j h a : r j [ i h a r j
hanger ]j?3?.r. • l!??.".??" i!?.?.n.?.r...
h i j j a i j j a i j [ h a i
} Khprseyl I I horse jjprs jjorsi ihprs ihprs
hug. i k g i i ^ 9 ;hM ; hogging. li A553 jJAS51 il^Sra. I
hands jjaens ljs n.ds ihxndz ihsendz
hops jjops jjaps .jhaps [haps
hopping Jjf?J?A0 1 l l M M i!?aJM...
yellow ii Ad?.o y ? d p o l l ^ d ? . 0 . . . { j | [jed?.©..
Initial/w/
wagon iw§rj.g3n iw?.9P.n !w.??S?n. Iw.?9?.n...
watch jwqtf j | j
watching iwajfirj iw9^?)m ;WA.t??n] bYMH...
wave i Y ^ J } . =
waving i w e??n] i I weisirj I
why jwai | j i n t o i / i / ' P'" '""' "'TJZILZIIZJ 'I.'' I l l
la JJA { ...i!iA |1A
laugh Jjaes j j j a e s i j s e f laughing ]JE?9L j ...]J.?.§!3 ll^lifJ.. leaf j j i s j j i s y j i s ijif leafy j j q s i j j i s i Ijisi i l i f i
135
Lyle ^ jaijo ] ihaijal ilaral jjaijo
Initial/r/ rabbit wsebrt iwEebit jwaebat iwaebit
radio weidioo jwedeoo jweideno jweidioo
read wid
reading winnj iwidirj
red wed jwed jwed jwed
roar woar jwor
row wo iwoo iwoo
rub wAb jwffib iWAb
rubbing wAbm jwAbin jWAbirj
APPENDIX 4
T H E R A P Y SESSION OBJECTIVES FOR B O T H SUBJECTS
APPENDIX 4
Therapy session objectives for Subject 1:
Block 1, cycles 1 & 2 and Block 2, cycle 1:
session 1. /h/ 2. Ihl 3. Ihl 4. /h/and/f/ 5. Ifl 6. Ifl 7. /f/ 8. review of cycle 9. mini probe
Block 3, cycle 1:
session 1. /sp/ and /sk/ 2. /sk/and/st/ 3. /sw/ and/kw/ 4. review of clusters 5. /d3/ 6. /d3/and/J7 7. /J / 8. review of cycle 9. mini probe
Therapy session objectives for Subject 2:
Block 1, cycles 1 & 2 and Block 2, cycle 1:
session 1. /sn/ (moraic) 2. /sp/ (moraic) 3. /tw/ (moraic) 4. review /sn/, /sp/, /tw/
/sk/ (onset-rime) 5. /sk/ and /st/ (onset-rime) 6. /st/ and /kw/ (onset-rime) 7. /kw/ (onset-rime) 8. review of cycle 9. mini probe
Block 2, cycle 2:
session 1. /J / 2. /J7and/d 3/ 3. /d 3 / 4 . review /J/ and M 3 / 5. /v/ 6. /v/and/f/ 7. /f/ 8. review of cycle 9. mini probe
Block 3, cycle 2:
session 1. /sp/ 2. /st/ 3. /sk/ 4 . /kw/ 5. /v/ 6. /f/and/v/ 7. /f/ 8. review of cycle 9. mini probe
Block 2, cycle 2:
session 1. IzJ (moraic) 2. /z/ (moraic) 3. /tw/ (moraic) 4. review IzJ and /tw/ 5. IU (onset-rime) 6. /I/ (onset-rime) 7. /kw/ (onset-rime) 8. review of cycle 9. mini probe
Therapy session objectives for Subject 2 (continued):
Block 3, cycle 1:
session 1. /z/ (moraic) 2. /z/ (moraic) 3. HI (onset-rime) 4. HI (onset-rime) 5. / d 3 / 6. /dj/and/J/ 7. / ; / 8. review of cycle 9. mini probe
Block 3, cycle 2:
session 1. / / / 2. /JV 3. /d3/ 4. / d 3 / 5. HI 6. /1/and/r/ 7. HI 8. review of cycle 9. mini probe