phonological therapy within a psycholinguistic framework

Research Report

Phonological therapy within a psycholinguisticframework: Promoting change in a child withpersisting speech difficulties

Michelle Pascoe, Joy Stackhouse and Bill Wells

Department of Human Communication Sciences, University of Sheffield,

Sheffield S10 2TA, UK

(Received 20 August 2003; accepted 14 July 2004)

Abstract

Background: Single case studies are a valuable means of providing informationabout the outcomes of speech and language intervention. Many previous studieshave used phonological analysis as a theoretical basis, while others have usedpsycholinguistic models. The present study combines these approaches toassessment, intervention and evaluation of outcomes.Aims: The aim of the research was to determine if intensive psycholinguisticallybased intervention could result in (a) specific and (b) generalized improvementsin the speech production of a child with severe and persisting phonologicaldifficulties.Methods and Procedures: A single subject research design was used with pre- andpost-intervention assessment carried out. Assessment took place at two levels:the macro level focused on global change in the child’s speech processingsystem using psycholinguistic speech profiling and phonological analyses;the micro assessment focused on specific, treated (and matched control)stimuli. There were three phases of intervention with a total of 30 hours oftherapy.Outcomes and Results: Micro evaluation showed significant changes in Katy’ssingle word and connected speech production – as well as in other areas such asspelling and auditory discrimination of closely related real word pairs. Macroevaluation revealed significant improvement in speech severity indices (PCC,PPC), and gains in her ability to discriminate between closely related real wordpairs. These changes were maintained at follow-up seven months afterintervention had ceased.Conclusions: Specific and intensive intervention brought about significantimprovements in this child’s speech, spelling and auditory discrimination at

International Journal of Language & Communication Disorders

ISSN 1368-2822 print/ISSN 1460-6984 online # 2005 Royal College of Speech & Language Therapistshttp://www.tandf.co.uk/journals

DOI: 10.1080/13682820412331290979

Address correspondence to: Michelle Pascoe, Department of Human Communication Sciences,University of Sheffield, Sheffield S10 2TA, UK. e-mail: hcpøø[email protected]

INT. J. LANG. COMM. DIS., APRIL–JUNE 2005,

VOL. 40, NO. 2, 189–220

the micro level, and in speech and auditory discrimination at a macro level. Themacro level assessments reveal persisting core deficits requiring further focusedintervention before changes can be observed more widely. When carefullydefined and evaluated, speech and language intervention can have positiveoutcomes for children with severe and persisting speech difficulties.

Keywords: phonological disorder, psycholinguistics, intervention, outcomes.

Introduction

There is an ongoing call for intervention studies in speech and language therapyliterature (Sommers, Logsdon and Wright 1992, Enderby and Emerson 1995,Frattali 1998, Crosbie and Dodd 2001, Gibbon, McNeill, Wood and Watson 2003).Intervention is of benefit not only to the individual child but also in contributing toevidence-based practice. Approaches to providing this evidence base differ: somehave emphasized the need for randomized controlled trials (RCTs), the ‘goldstandard’ of efficacy research (e.g. see Fahey, Griffiths and Peters 1995, Glogowska,Roulstone, Enderby and Peters 2000). Others have carried out effectiveness studiesin real life clinical settings focusing on a single child, or small numbers of individualchildren (e.g. Broom and Doctor 1995, Holm and Dodd 1999, Crosbie and Dodd2001, Spooner 2002). Each of these approaches has value: RCTs are a powerfulmeans for testing experimental hypotheses using methods designed to reduce bias.However, such studies may fail to provide information on how intervention works,the duration or intensity of intervention that is needed to bring about change, or thespecific details of treatment that may be effective in the treatment of certainindividuals (Frattali 1998). Single subject designs are able to answer some of thesequestions, and solve the problems associated with subject homogeneity in thatsubjects serve as their own control. Single case studies afford the opportunity to ‘getinside therapy’ as urged by authors such as Clark and Elliot (1992) and Byng, Vander Gaag and Parr (1998).

Intervention studies have value not just in their contribution to the efficacydatabase, but also in terms of increasing our theoretical knowledge (Bishop 1998,Baker, Croot, McLeod and Paul 2001). Psycholinguistic models can be used todevelop and test theories about the processes that underlie speech production inindividual children. When the intervention is carried out in a controlled way, theoutcomes of the programme allow one to return to the theoretical starting point,and reconsider the nature of the speech and language processing system.

Psycholinguistic approaches to the assessment and remediation of speech-disordered children are well established (e.g. Stackhouse and Wells 1997, 2001; Chiat2000). Such approaches are valuable in giving clinicians a theoretical base fromwhich to drive the intervention process. Psycholinguistic assessment relies ontheoretical models of speech processing from which hypotheses about the level ofbreakdown leading to the speech difficulties can be generated and systematicallytested (Stackhouse and Wells 1997). The aim is to find out where on the model thechild’s speech processing skills are breaking down, and to consider how one mightremediate these difficulties. Examples of model-based interventions include thesingle case studies reported by Bryan and Howard (1992), Broom and Doctor(1995), Waters, Hawkes and Burnett (1998), Norbury and Chiat (2000), Crosbie andDodd (2001), Spooner (2002) and Stiegler and Hoffman (2001).

190 M. Pascoe et al.

Psycholinguistic approaches have developed partly in response to dissatisfactionwith more traditional medical diagnostic categories. The traditional approach to theclassification of speech and language disorders does not focus on each person as anindividual with a unique deficit in his or her processing system. The focus is ongrouping people with broadly similar aetiologies or symptoms, by implicationsuggesting that the same treatment might be applicable to all members of the group.However, studies have shown that children with superficially similar speechdifficulties may have very different patterns of underlying processing deficit (e.g.Ruscello 1995, Stackhouse, Nathan, Goulandris and Snowling 2002, Chiat 2000,Dodd and Bradford 2000). The psycholinguistic approach is concerned withinvestigating underlying processing skills. If intervention is carefully targeted at anindividual’s specific point of breakdown, and carried out with an awareness of thestrengths and weaknesses that underlie the individual’s speech processing system,then it seems more likely that (a) intervention will be successful in bringing aboutchange in the speech processing system, and (b) if intervention is not successful thenit is possible to isolate the level of the speech processing system that therapy taskswere tapping, and make appropriate revisions.

However, speech and language processing models have inherent limitations, andeven if further refined, it is doubtful if they could ever shape the clinical process inisolation. Not all single case studies use psycholinguistic models as their theoreticalspringboard. Many single case studies have relied mainly on linguistic theory andphonological analyses in planning and evaluating interventions (e.g. Weiner 1981,Monahan 1986, Saben and Ingham 1991, Bernhardt 1992, Barlow 2001). This paperaims to show how a psycholinguistic approach can be combined with a linguisticapproach in intervention with a school age child with a phonological disorder. Theintervention study draws on knowledge from two key areas: developmentalpsycholinguistics and child phonology. It is suggested that the psycholinguisticapproach is useful in answering the question: ‘How?’ - How is intervention going towork, i.e. how is change to be brought about in the individual’s speech processingsystem? Knowledge from linguistics – in this case phonology - enables us to answerthe more specific ‘what?’ question, i.e. what is the content of intervention? e.g. whatare the stimuli that will be used in the activities?

There are few model-based intervention case studies that have attempted tocouch phonological intervention within an explicit psycholinguistic framework.Bryan and Howard (1992) described intervention for a five-year-old child withsevere phonological difficulties. The child’s speech processing difficulties wereinvestigated through a series of psycholinguistically-motivated tasks and interpretedin the light of current models of speech and language processing. In addition aphonological analysis of the child’s surface speech errors took place, with both setsof data used to inform intervention planning. Waters et al. (1998) more explicitlyemphasized the need to integrate psycholinguistic information with phonologicalinformation in their report of intervention with a five-year-old boy withunintelligible speech. They suggested that while phonological analysis andpsycholinguistic assessment are essential for a principled approach to intervention,they may not always be sufficient: children’s attitudes, behaviours and preferredlearning styles also need to be taken into account. More recently Ebbels (2000)investigated the speech and language processing skills of a 10-year-old child with ahearing impairment. Specific points of breakdown for individual phonologicalcontrasts were identified, with detailed input and output phonological analyses

Phonological therapy within a psycholinguistic framework 191

interpreted within a broader psycholinguistic framework. The results of theinvestigation showed that for some children there is not a single level of breakdown,but rather there may be multiple levels of difficulty with specific phonologicalcontrasts implicated at particular levels.

Each of these papers approached assessment and intervention in different ways.However, they share a common concern with the nature of their participant’sunderlying phonological representations. Edwards, Fourakis, Beckman and Fox(1999) outline the evolution of representation-based approaches to understandingchildren’s phonology, and suggest that characterizing children’s phonologicalcompetence in terms of representations and the constraints acting on them allowsfor a richer conceptualisation of phonological development, than traditionalderivational and ‘normalizing’ approaches. A further reason for careful investigationof underlying phonological representations and phonological processing ability isbecause of the close relationship between these skills and reading and spellingabilities. The association between phonological processing difficulties and readingand spelling problems has been shown in a number of single case studies (e.g.Campbell and Butterworth 1985, Snowling, Stackhouse and Rack 1986) andexperimental investigations comparing dyslexic children with normally developingreaders (e.g. Wagner and Torgeson 1987). For school-age children with persistingspeech problems, understanding of the child’s underlying difficulties can haveimportant implications for speech, language and literacy support.

In this study, we describe the assessment, intervention planning, interventionand evaluation that took place with a girl aged 6;5 at the start of the study. The child,who we call Katy, had severe and persisting speech difficulties. The aim of theresearch was to determine if psycholinguistically-based intervention could result in(a) specific and (b) generalized improvements in the speech production of a childwith severe and persisting difficulties.

Methods and Procedures

Participant

The participant, Katy, was aged 6;5 years at the start of the project. Katy has nohearing difficulties and comes from a monolingual English home where she liveswith both parents and one older sibling. Katy attends a mainstream school whereshe has a statement of special educational needs. This provides for a learningsupport assistant who works with her in the classroom as well as taking her out ofthe classroom for additional one-to-one support. This includes work on her speechthat is carried out under the guidance of a National Health Service speech andlanguage therapist. IQ results (WASI, Wechsler, 1999) indicated a verbal IQ of 83(low average), a performance IQ of 78 (borderline) and a full scale IQ of 78. Katy’sclass teacher described her as being in the ‘weaker ability group’ for all her subjects.She is described as a popular girl with many friends, who enjoys school despite herdifficulties.

Katy has a history of receptive and expressive language delays, although herexpressive delay outweighs her receptive delay. From approximately age 2;0 sherelied heavily on gestures and pointing in order to communicate. At the start of theintervention project, Katy was in her second year of formal schooling and remainedhighly unintelligible to unfamiliar listeners. Further details of Katy’s speech


difficulties and her speech and language intervention history are presented in thefollowing section.

Intervention history

Katy has been known to the local speech and language therapy service from the timethat she was 2;0 years, and has had regular periods of therapy. These are outlined intable 1 which shows that intervention has focused mainly on general communicationand early language development, with some specific sessions focusing onarticulation, and more recently phonological therapy with incorporation ofphonological awareness. Progress made has been limited and Katy’s attention hasoften been described as limited for her age, making both therapy and follow-upwork at home challenging. During the intervention project, Katy received noadditional direct speech and language therapy. In addition to the normal classroominstruction she attended a ‘speech and listening group’ twice a week for half an hour.Five children were in the group run by a learning support assistant. This groupinvolved general language stimulation activities and phonological awareness work,e.g. clapping of syllables, identification of initial and final sounds.

Speech difficulties

The Phonological Assessment of Child Speech (PACS) (Grunwell 1985) andEdinburgh Articulation Test (EAT) (Anthony, Bogle, Ingram and McIsaac 1971)were used to assess Katy’s speech. Table 2 outlines the findings from theseassessments.

The severity of Katy’s speech difficulties was estimated by using PCC(percentage of consonants correct), PVC (percentage of vowels correct) and PPC(percentage of phonemes correct) indices following guidelines from Shriberg,Austin, Lewis, McSweeny and Wilson (1997) and Dodd (1995), and a set of 100randomly selected single words. Katy has difficulties with both accurate vowel andconsonant production. Her speech difficulties were severe with only 22% ofconsonants accurately realized in single words. Her syllable structure is typicallyopen (CV, CVCV). Katy’s phonetic inventory shows a marked mismatch betweenthe contrasts available to her word-initially and medially, and those she is able toindicate word finally. She has all plosives in her word initial and medial repertoire,and other consonants emerging in these word positions. In word final position herrepertoire evidences no consonants. She was stimulable for a wide range of soundswith the exception of /v/, /ð/, /#/, / /, /t#/.

Guidelines from PACS were used to yield percentage usage of each phonologicalprocess by counting the number of instances of use of a particular process inrelation to the potential opportunities for use of each process. The predominantphonological processes found in Katy’s speech were (1) cluster reduction (100%) inwhich clusters are typically reduced to one element that is realised as a substitution(e.g. /sp/ and /st/ typically produced as [b] and [d] respectively), (2) final consonantdeletion (96%), (3) pre-vocalic voicing (40%), (4) stopping of fricatives and affricates(21%) and (5) gliding (21%). Vowel distortions were the main example of deviantprocesses in Katy’s speech and these are likely due to her motor difficulties.


Table 1. Summary of Katy’s speech and language intervention history

Katy’schronological age(years; months) Description Duration Comments

2;3 General advice onlanguage developmentgiven in home

66weeklyvisits

Concerns aboutdelayed speech

3;0 Non-directive,multidisciplinary therapyat child development centre

Unknown Focus on signing,Makaton andneuro-developmentaltherapy

3;6 Therapy block focusingon use of Rebus symbolsas well as oral-motorexercises ‘to addressarticulation problems’

66weekly No commentsmade regardingprogress. Katythought to bemore confident

4;2 Instrumentation to provideincreased feedback usedin university clinic

106weeklysessions

Some limitedimprovementnoted in CVproduction.CVCV remainsmore challenging

Nursery 4;4 Observation and advicegiven to nursery staff

One visit Increased usedof gesture andpointing; increasinglysociable

Reception/Year 1 5;1

Syllable clapping toimprove awareness oflength and timing; expandrepertoire of consonantsto include /p, m, b, d,n, c/ in word final position

Two to threetermly visitsfrom speechand languagetherapist. Speechand languagetherapist’sprogramme carriedout on daily basisby learning supportassistant in 1:1sessions orsmall groups

Increased awarenessof word finalconsonants; withinword consonantsbeginning to emerge

Year 2 6;1 Continuation ofprogramme from Year 1

As for Year 1 Concerns emergingre influence ofspeech on spelling;improved productionof final consonantsat single word levelbut limitedgeneralization tosentence level; increasedawareness of listener’sneeds; intelligibilityremains poor


In terms of connected speech, Katy’s PCC was 25%, similar to that of her singleword speech. Her speech rate is typically slow and gives the impression of beingsyllable timed rather than stress timed.

Design

A single subject research design was used with pre- and post-interventionassessment carried out. The research design is shown in figure 1. Three phases of

Table 2. Katy’s speech data at pre-intervention assessment (T1)

Assessment Comments

Severity indices Percentage consonants correct (PCC): 22%Percentage vowels correct (PVC): 74.1%Percentage phonemes correct (PPC): 41.9%

Phonetic inventory Word initial position: [m, n, p, b, d, t, k, c, f, w, j, r, ]Word medial position: [m, b, d, t, k, c, w]Word final position:

Stimulability All consonants except /v/, /ð/, /#/, / /, /t#/Phonological processesanalysis (per cent use)

Developmental processes: cluster reduction (100%); finalconsonant deletion (96%); prevocalic voicing (40%); stoppingof fricatives and affricates (21%); gliding (21%)

Non-developmental processes: vowel distortion (25%)Single-wordspeech sample

[bæ] for BAG [æ"b ] for APPLE

[we] for WEB ["gæwI] for GARAGE

[vI] for FISH ["vebe] for VEGETABLES

[gI"me] for CHRISTMAS [dI] for SINK

[bæ] for PRAM [jaI] for LIGHT

[e] for EGGS [ki:] for QUEEN

[bI] for BEES [gæ] for CLASS

Connectedspeech sample

[k: le: w "ab ua ] for HER LEG WAS BROKEN

[a l l taI "a g u] for A LONG LONG TIME AGO

[I "bet na] for ITS BETTER NOW

[aaI aæ "peItap i: a "wedI] for I HAD PLAYTIME ALREADY

[I "pw .bI "dIa taI na] for ITS PROBABLY DINNER TIME NOW

Figure 1. Research design.


intervention took place with each phase involving a different treatment. Baselinetesting was carried out at two levels: initially a ‘macro assessment’ was carried out toobtain a broad picture of Katy’s speech processing skills (T1a). A range of speechand language tests was administered. Data from these tests assisted in interventionplanning, and resulted in the development of a specific set of stimuli to be used inintervention. Baseline measures (T1b) were then obtained to provide information onKaty’s processing abilities directly related to the stimuli set to be used in therapy, inwhat is referred to in this paper as the ‘micro assessment.’ The difference betweenKaty’s speech severity indices (PCC, PVC and PPC) at T1a and T1b was not asignificant one (t(99)52.575, n.s) indicating a stable pre-intervention baseline. Re-assessment at the micro level was carried out on completion of each interventionphase (T2, T3, T4a) to identify changes over the course of intervention. The study iscompleted with a return to the macro assessment (T4b) to allow for a more globalevaluation of any changes that have occurred. Finally longer-term follow-up tookplace 7 months after the completion of intervention (T5), to evaluate maintenanceof any progress that had occurred. This follow-up assessment involved both macroand micro assessment. No speech and language therapy took place between T4and T5.

Macro assessment and intervention planning

(a) The psycholinguistic perspectiveThe speech processing profile and model developed by Stackhouse and Wells (1997)were used for organizing and understanding the macro assessment data. The speechprocessing profile is a clinical tool which allows clinicians to consider potential levelsof breakdown in the speech processing system by asking questions such as: ‘Can thechild access accurate motor programs?’ and ‘Can the child discriminate betweenreal words?’ At each level of the profile, tests were carried out in order toprovide answers to these questions. Katy’s speech processing profile is presented infigure 2.

In terms of input processing Katy had specific difficulties in discriminatingbetween non-words (level B) as well as between real words (level D). On theoutput side she shows a range of difficulties at each of the successive levels.She experienced difficulties in picture naming tasks (level G), phonologicalmanipulation (level H, e.g. spoonerism tasks), real and non-word repetition tasks(levels I and J) and some oro-motor tasks at level K. Results of the receptivelanguage and literacy assessments not incorporated on the speech processing profileare shown in Table 3.

The speech processing profile is based on a speech processing model – a boxand arrow model used by Stackhouse and Wells (1997) to conceptualize speechprocessing and production. Task analysis and comparison led to the development ofhypotheses about the loci of Katy’s speech processing deficits. Figure 3 illustrateswhere Katy’s main areas of difficulty are on this model.

Katy’s difficulties included phonological recognition on the input side, andretrieval of stored motor programmes, creation of online motor programmes andmotor planning on the output side. These levels of processing are discussed infurther detail below.


Figure 2. Katy’s Speech Processing Profile at age 6;5 (from Stackhouse and Wells 1997) !5ageappropriate performance X51 s.d below the expected mean for her age; XX52 s.d belowthe expected mean for her age.


& Input processingKaty experienced many difficulties with the auditory discrimination of real and non-words, suggesting that she was not able to recognize fine phonological differences,i.e. phonological recognition (in Figure 3). Her phonological representations werehowever, found to be relatively accurate. It is difficult to specifically tap intophonological representations without processing being affected by weaknesses inauditory discrimination. Katy performed in an age-appropriate way when asked toidentify rhyme and alliteration from pictures (level F, figure 2). Specially devised‘posting tasks’ were carried out to provide information about Katy’s phonologicalrepresentations and the sound contrasts involved. The format of these tasks was tointroduce Katy to two post-boxes, each one used for posting of a different sound,e.g. pictures of /b/ words (e.g. BAT, BEE) into a green box, and pictures of /s/ words(e.g. SAT, SEE) into a red box. Katy was required to pick up picture cards and putthem into the relevant box. The therapist did not name the items for the child. Katyperformed well on these tasks: obtaining or approximating 100% for all tasks withboth word initial and word final contrasts. Most challenging for her was the voicingcontrast of /p/ and /b/ where she favoured the /b/ box and scored correctly ononly 75% of items. Katy did have voicing errors in her speech and typically voicedplosives pre-vocalically. It was concluded that for Katy phonological representationsare a relative strength.

& Retrieval of stored motor programmes and creation of online motorprogrammes

Picture naming will involve a child’s access of semantic information and a linkedmotor programme. Real word repetition tasks do not necessarily involve access of

Table 3. Summary of Katy’s receptive language and literacy assessment at CA 6;5

Assessment Area tapped Standard score Centile Age equivalent

Receptive languageTest for thereception ofgrammar (TROG;Bishop 1989)

Receptivegrammar

95 40 6;0

British PictureVocabulary Scale(BPVS; Dunn et al.1997)

Receptivevocabulary

80 10 4;6

Literacy measuresSchonell GradedReading Test(Subtest of AstonIndex; Newton andThompson 1982).

Readingsingle words

reading age56;8 years

Schonell SpellingTest (Subtest ofAston Index,Newton andThompson 1982)

Writing singlewords fromdictation

spelling age55;9


lexical representations, and non-word repetition tasks cannot by definition involvethe lexical representation. Non-word repetition tasks tap auditory input processing,phonological representations (in order to check that there is no phonologicalrepresentation) and the mapping of this input form by means of the online motorprogramming device onto an output form. Unlike the children described in otherstudies who were found to have notable differences between naming and repetitionskills (Ebbels 2000) and real and non-word production (Bryan and Howard 1992),Katy was found to have equally low scores for each of these tasks. Because non-word repetition and picture naming involve distinct processing routes, it washypothesized that both the stored motor programmes (central to picture naming)and the online motor programming (central to non-word repetition) were affected.The tasks carried out at level H (figure 2) of the speech processing profile, thespoonerism task and rhyme generation task, suggested that Katy may have somedifficulty with the internal processing required to manipulate these phonemes andcreate new motor programmes. However, because her speech difficulties are severeit was difficult to accurately judge her ability to carry out these tasks.

Figure 3. Speech processing model (from Stackhouse and Wells 1997) with circled areas indicatingKaty’s main areas of difficulty.


& Motor planningMotor planning is considered to involve phonetic aspects of speech production,moving beyond the abstract linguistic knowledge of the previous stage. It is at thislevel that co-articulation comes into play. While motor programming is conceived asbeing a single word level, motor planning involves the connection of words intostrings of speech. Katy’s speech production at a connected speech level had a similardegree of accuracy to her single word speech. Many of the words in her connectedspeech were produced as single words with primary stress and many pauses betweenitems that would normally be elided or assimilated in the connected speech ofnormally developing children (Newton and Wells 2002). It was considered that oncemotor programmes had been revised, motor planning might need to be morespecifically addressed.

Katy had difficulties with both input and output processing. The first importantintervention-planning question was whether to address input (auditory discrimina-tion) or speech production. This is a question that has been frequently debated inthe literature (e.g. Locke 1980, Evershed Martin 1991, Bird and Bishop 1992,Rvachew 1994, Rvachew, Rafaat and Martin 1999, Waters 2001). Bishop, Brown andRobson (1990) found that children with severe speech output difficulties - like Katy- typically have difficulties in discriminating between similar items, particularly non-words. They suggest this is because such children have had limited opportunities toexperiment and play with related sound strings in the way that normally developingchildren do. This theory would suggest that Katy’s discrimination difficulties aresecondary to her speech problems, and thus intervention targeted at the speechproblems may have the effect of improving her discrimination abilities.

Focusing on Katy’s range of output difficulties, which level of processing shouldintervention target? Katy has been diagnosed with ataxic cerebral palsy and hassome muscular weakness (level K of the speech processing profile, figure 2).However, detailed assessment at this level revealed that Katy’s sound productionskills are adequate for speech: she was able to produce all speech sounds in isolationand had no specific difficulties in terms of the strength, range of movement or co-ordination exhibited during speech (and non-speech tasks). Katy’s difficulties beginat the single word level of speech, and her difficulties are concentrated on the outputside of the profile.

It is important to consider children’s strengths and weaknesses in interventionplanning. Katy’s relative strengths included her orthographic knowledge, hersemantic knowledge and her phonological representations. She enjoyed writtenlanguage activities and showed age-appropriate letter knowledge. Interventionwould ideally involve activities that give Katy explicit opportunities to use herstrengths. Thus activities could include reading (drawing on her orthographicawareness), meaningful minimal pair work (drawing on her semantic knowledge)and tasks involving picture naming which give Katy the opportunity toaccess her own (relatively accurate) phonological representation and relate it tothe (inaccurate) stored motor programme, giving her the opportunity to revise thelatter.

(b) The phonological perspectiveThe Phonological Assessment of Child Speech (PACS) (Grunwell 1985) andEdinburgh Articulation Test (EAT) (Anthony et al. 1971) were used for thephonological analyses, to aid in intervention planning and stimuli selection, i.e. what


stimuli would be used in the activities outlined in the previous section? Table 2outlined the findings from these assessments.

‘Whole word phonology’ is a widely accepted way of conceptualizing children’searly phonological patterns (e.g. Ferguson and Farwell 1975, Macken 1979, Vellemanand Vihman 2002). In recent years this theory has been applied to clinical settings.Velleman (2002) describes ‘phonotactic therapy’ as an intervention for unintelligiblechildren which focuses on building up accurate phonotactic frames, before focusingon ‘filling up’ the phoneme slots within the frames with accurate phoneticrealizations. Along similar lines, Stackhouse and Wells’ psycholinguistic frameworkincludes a developmental phase model of speech and literacy in which the ‘wholeword’ phase is one of the earliest phases of speech development, preceding the‘systematic simplification’ phase in which systematic substitutions dominate(Stackhouse and Wells, 1997: 197, 2001:410). Katy’s speech output showscharacteristics of the whole word phase: she relies heavily on CV syllable structure.Expanding her potential syllable structures to include CVC, would enable her tomake a much greater range of lexical contrasts. Although she has some patterns (e.g.stopping) characteristic of the systematic simplification phase, it was developmen-tally appropriate to focus intervention on the earlier whole word phase.

The intervention programme aimed to encourage Katy to produce exemplars ofthe CVC frame. However, children do not talk in single words, and the ultimate aimof the intervention was for Katy to use final consonants in CVC words embedded insentences. In order to reach these goals, three phases of therapy were devised asfollows:

– Phase I: therapy on a specific set of single words– Phase II: therapy on a wider range of single words– Phase III: therapy on connected speech

Three lists of stimuli (lists A, B and C) were devised (table 4). Lists A and B weredesignated as treatment lists. In phase I of intervention, lists A and B would be

Table 4. Matched lists of stimuli

Item number List A List B List C

1 NOTE BOAT GOAT

2 PLANE RAIN TRAIN

3 HEART CART PART

4 NAIL WHALE HAIL

5 CAGE AGE PAGE

6 SLIDE HIDE LIED

7 WHEEL SEAL KNEEL

8 RAKE CAKE STEAK

9 STORK FORK WALK

10 LEAF HALF HOOF

11 SAUCE FLEECE PURSE

12 ICE SLICE DICE

13 SOAP ROPE GRAPE

14 PIPE PEEP SHEEP

15 BARN DAWN LINE

16 ROAD SWORD TOAD


treated in different ways. Words in list A were used in speech production tasks thatincluded explicit consideration of spelling. This involved making links betweenwritten and spoken word forms targeted in the intervention, i.e. drawing Katy’sattention specifically to final consonants in written forms. List B was used in speechproduction tasks that did not involve written forms. In subsequent phases ofintervention, list A and B were not differentiated. List C was randomly selected as anon-treatment control list.

The selection criteria for stimuli are listed below.

(a) Each list consisted of 16 monosyllabic words.(b) CVC words were favoured, although in some instances CCVC words had

to be used since all requirements for matched items could not be met.Where CCVC words were selected they were matched across the three lists.

(c) Items were matched in terms of rhyme across the three lists. Where rhymecould not be matched, items were matched by coda segment.

(d) Items were matched across the lists for age of acquisition and spokenlanguage frequency using the MRC psycholinguistic database (http://www.psy.uwa.edu.au/mrcdatabase).

(e) Irregular orthographic forms were weighted in terms of their complexityand balanced across the lists.Items were chosen to highlight the functional importance of finalconsonants and, thus were words that, with the final consonant removed,made another real-word minimal pair (e.g. BOAT/BOW). The vowel nucleuswas therefore either a long vowel or a diphthong.

Details of stimuli for the single word phases of intervention have been provided.Stimuli for the connected speech phase of treatment (phase III) were also chosenaccording to phonological criteria. A graded hierarchy of sentences was devisedaround each of the target single words shown in table 4, moving from a facilitatorycontext to a more demanding one. For example, in the case of the target word ROPE

the facilitatory sentence used as a starting point was: THIS ROPE PULLED THE CAR,where the onset consonant of the following word PULLED is the same as the codaconsonant of the target word ROPE. Given her phonological abilities at the beginningof the study, it was thought that Katy should be able to produce the initial [p] inPULLED even if she omitted the final [p] in ROPE. In order to achieve an acceptablerealization of this final consonant, she would merely have to lengthen the closurephase for the (single) consonant articulation. At the next level, Katy would berequired to produce a sentence such as THERE’S ROPE ON THE ROAD with the targetROPE being followed by a vowel. Most challenging was a sentence such as THIS ROPE

GOT FRAYED where she was required to change her place of articulation (and voicing)between the final [p] in ROPE and the following consonant [c].

Summary

Macro assessment and intervention planning focused on providing answers to twoquestions: (a) How will intervention be carried out, i.e. types of activities to becarried out (b) What would the content of these activities be, i.e. what phonologicalstimuli would be used in the activities? Psycholinguistic profiling addressed (a): itwas suggested that intervention should give Katy opportunities to revise and update

(f )


her stored motor programmes. Her relative strengths such as reading, makingphonological judgments (that do not rely on auditory input) and using semanticknowledge to distinguish between minimal pairs in meaningful contexts wereconsidered important ways that could be used to bring about change in motorprogramming. The linguistic approach addressed (b): the specific pattern of motorprogramme to be addressed was CVC words since this fundamental template waslacking from Katy’s motor programme store.

Micro assessment and baseline measures

Pre-intervention baseline assessment was carried out. For each of the items in listsA, B and C (Table 4), Katy was required to

(a) name pictures of each of the target single words(b) produce the target single word in a short phrase (‘the TARGET in the

picture’)(c) write the target single words(d) discriminate between the target single word and a closely related item that

differed only in terms of the final segment in spoken production (e.g. arethese word pairs the same or different: ROPE and ROW? ROPE and ROTE?).

This set of tasks constituted the micro assessment. It was carried out as a pre-intervention baseline and after each phase of intervention.

Research questions

This project aimed to determine whether Katy could make significant progress inspeech production when given intensive phonological therapy structured within aframework of psycholinguistic assessment. More specific questions were formulatedregarding her progress in a range of areas including speech at a single word andconnected level, spelling, and auditory discrimination. Table 5 summarizes these questions.

Intervention

Intervention was carried out in Katy’s school on a twice-weekly basis. Sessions lastedfor one hour each time, with ten hours of intervention being given in each phase.Therapy took place in a quiet room with only the child and therapist present. Allintervention sessions were audio taped using a SONY MZ-R30 portable minidiscrecorder, with the child and her parents’ consent. Most of the sessions involvedtabletop activities and games, e.g. minimal pair card games, barrier games, boardgames, making pictures and reading stories. Katy was 6;8 at the start of theintervention itself and was 7;5 on completion of the final phase of intervention.Further details of the intervention aims and activities for each phase are providedbelow.

Phase I

Aim: To increase Katy’s awareness of final consonants and encourage her toproduce CVC stimuli items from the treatment lists A and B as listed in table 4.


& List A items were worked on with explicit use of written forms& List B items were given a speech-only treatment without the associated

literacy activities.& In order to avoid confusion between the two types of intervention, odd-

numbered sessions addressed list A stimuli with the speech-spellingtreatment, and even-numbered sessions worked on stimuli from list B.

Phase II

Aim: To encourage generalization of CVC production to a broader range of singlewords.

& Intervention in this phase was guided by broad themes (e.g. animals,numbers, household objects).

& Sessions gave Katy the opportunity to produce CVC words in a wider andmore natural range of contexts.

& Written forms of the words were used to remind Katy about her finalconsonant production in some instances, together with silent posting tasksand ‘meaningful minimal pair’ activities (following Weiner 1981) which alsoincorporated exposure to written forms.

Phase III

Aim: To facilitate production of CVC items from lists A and B in sentences gradedin terms of phonetic difficulty.

& Intervention in this phase revolved heavily around literacy.& Katy was required to read the stimuli sentences written below illustrations of

the items, as well as matching sentences with appropriate pictures.

Table 5. Questions about the intervention programme

Area Question

Single wordspeech

Will phase I intervention result in an increased count of final consonantsin the treated word lists A and B?

Will exposure to orthographic forms promote faster learning,i.e. after phase I will list A (speech and spelling treatment) show moreimprovement than list B (speech only treatment)?

After intervention phases I and II, will Katy’s final consonant count(FCC) for list C (untreated controls) also improve beyond chance level?

Connectedspeech

Will Katy’s FCC for target words used in a short carrier phrase improvein phase I and II, as Katy’s speech processing system is modified?

Phase III specifically addresses connected speech. Will it result in significantlyincreased FCC’s in connected speech productions in the treatment lists A and B?

After intervention phase III, will Katy’s FCC for list C items(untreated controls) in connected speech also improve beyond chance level?

Spelling Will Katy’s ability to indicate final segments in spelling improve following threephases of intervention for speech?

Auditorydiscrimination

Will improved speech production result in improved ability to discriminatebetween treatment stimuli and phonetically similar words?

Will increased experience with production of final consonants result inimproved discrimination of novel words that differ in terms of final segments?


Results

Micro evaluation

Results from the micro evaluation are considered in terms of each of the mainareas measured: single word speech, connected speech, spelling and auditorydiscrimination.

Single word speech

The results for Katy’s single word speech production over the three phases oftherapy and at each of the assessment points are presented in figure 4.

Overall, a statistically significant main effect for intervention was found usingtwo-way mixed ANOVA (F(2, 44)538.310, p,.001). Katy’s single word productionwas assessed by means of a picture-naming task that formed part of the baselinemicro assessment, and was carried out following each successive phase ofintervention. The focus of the assessment was on Katy’s final segment production:she was awarded two points for final consonants that were accurately realized, onepoint for using an inaccurate final consonant, and no points for omission of a finalconsonant. Raw scores were converted to percentages. Two-tailed paired samplest-tests showed significant gains for each of the stimuli lists from baseline (T1) topost phase I (T2) (list A treated words, t(15)524.392, p5.001; list B treated words,t(15)527.652, p,.001; list C untreated words, t(15)24.038, p5.001). Furthersignificant gains were made with treated items in list A and the untreated items in listC from T2 to T3 (t(15)523.955, p5.001), following phase II, with the treated itemsnow approaching ceiling at 94%. However, at T4 reassessment, followingintervention phase III that targeted connected speech, there was a significantdecrease in performance on final consonant production in CVC words for each ofthe three lists (list A treated words, t(15)53.416, p,.005; list B treated words,t(15)54.392, p5.001; list C untreated words, t(15)53.101, p,.05). At long-termfollow-up (T5) following a period with no intervention, significant gains were made

Figure 4. Katy’s single word speech production.


from T4 (t(31)522.47, p,.05) for the treated words. For the matched untreatedcontrols there was no significant change after intervention ceased from T4 to T5.

Connected speech

Katy’s ability to produce CVC words in connected speech was assessed by asking herto repeat the stimuli items in a short carrier phrase. As for the single word speechassessment, the focus was on Katy’s final segment production of the stimuli words:she was awarded two points for final consonants that were accurately realized, onepoint for using an inaccurate final consonant, and no points for omission of a finalconsonant. Raw scores were converted to percentages. Results are shown in figure 5.

A statistically significant main effect for intervention was found using two-waymixed ANOVA [F(2, 44)5108.477, p,.001]. Initially, Katy found this a verychallenging task and did not use any final consonants in connected speech at the T1pre-intervention assessment, or T2 or T3 assessments. However, followingintervention phase III which specifically targeted connected speech at the T4assessment, there was a significant change [F(2, 45)567.623, p,.001] for each of thethree stimuli lists. Her treated word performance for connected speech did notchange significantly after intervention ceased between T4 and T5. For the matcheduntreated controls (list C), further significant gains were made from T4 to T5(t(15)523.093, p,.01) for this set of stimuli.

Spelling

Katy’s written output of the CVC targets was investigated using a single worddictation task. As for the other assessments, the focus was on Katy’s final segmentproduction of the stimuli words: she was awarded two points for final consonantsthat were correctly written, one point for the use of any final consonant, and nopoints for omission of a final consonant. Raw scores were converted to percentages.Results are shown in figure 6.

Katy’s written representations of the targets were significantly more accuratethan her spoken representations pre-intervention (t(47)55.657, p,.001) and at

Figure 5. Katy’s CVC production in connected speech.


long-term follow-up (T5) (t(47)53.483, p5.001). However, the effect size for singleword speech (eta squared5.635) was greater than that for spelling (etasquared5.390). Overall, a statistically significant main effect for intervention wasfound using two-way mixed ANOVA [F(2,44)514.083, p,.001].

For the list A and B treated items, steady but not significant increases were notedat each assessment when compared to the previous evaluation. The change overallfrom T1 to T5 was a significant one (t(31)522.6, p,.05). For the untreated itemsin list C, a significant increase was noted when comparing scores from T3 with thoseat T4 (t(15)522.739, p,.05). Untreated items improved significantly after the finalphase of intervention and these gains were maintained at the long-term follow-upat T5.

Auditory discrimination

Katy’s auditory discrimination skills were investigated by asking her to make same/different judgments about pairs of closely related words (e.g. ROPE/ROTE). Results ofKaty’s performance on this task are presented in figure 7.

At T1 assessment, Katy found the task relatively easy with scores between 70and 90% for the wordlists A, B and C. Overall there was not a significant main effectof time. However, some significant changes were noted on the list A items: whencomparing Katy’s performance at T1 with T2 (t(15)522.782, p,.05) and whencomparing her overall discrimination performance on the list A words from T1 withT5 (t(15)522.150, p,.05). No significant changes were noted for the untreatednon-word items.

Macro evaluation

The macro assessment procedures carried out at the start of the project were re-administered on completion of the three intervention phases at T4 in order to

Figure 6. Katy’s written production of CVC stimuli.


evaluate the intervention from a global perspective, and again at T5 some sevenmonths later to evaluate maintenance of progress following a period with nointervention taking place.

(a) Psycholinguistic perspectiveTests used to build up the original speech processing profile at CA 6;5 (Stackhouseand Wells 1997, see figure 2) were re-administered. It was found that Katy’s profile atCA 7;7 (and CA 8;2) was largely unchanged from the initial profile (figure 8). Onlyone of the levels revealed changes: that of level D, which poses the question: ‘Canthe child discriminate between real words?’ Katy showed improvement on threeassessments carried out in order to tap this level (Wepman and Reynolds 1987,Newton and Thompson 1982, Bridgeman and Snowling 1988). She now performedat an age appropriate level for each of these tasks. However, at level B (‘Can thechild distinguish between non-words?’) no improvement was noted. On the outputside of the profile no significant gains were made at any level.

Reporting standardized test results for children with severe speech results canmask true change. Although comparisons with chronologically-matched peer groupscan provide evidence of functional gains, these tests are not sensitive in theirevaluation of children with severe difficulties. The following section provides furtherqualitative information about changes in Katy’s speech from a macro perspective.

(b) Phonological perspectivePhonological analyses using the PACS (Grunwell 1985) and EAT (Anthony et al.1971) were carried out in order to evaluate changes in Katy’s phonology after theintervention. Results are summarized in Table 6.

Katy made significant gains with her PPC (t(99)524.662, p,.001) whencomparing results from T1 with those at T5. Significant gains were made for PCC(percentage consonants correct) from pre- to post-intervention (t(99)526.051,p,.001). Her PVC (percentage vowels correct) did not change significantly frompre- to post-intervention. Her word final phonetic inventory expanded although sheis not yet able to use all phonemes to realize appropriate contrasts. She is now ableto produce all plosives and nasals - although not always appropriately - incomparison to her complete lack of consonants available in this position prior to

Figure 7. Katy’s auditory discrimination judgments of closely related CVC word pairs.


Figure 8. Katy’s Speech Processing Profile at age 7;6 (from Stackhouse and Wells 1997) with areasof changed performance highlighted. !5age appropriate performance; X51 s.d below theexpected mean for her age; XX52 s.d below the expected mean for her age.


intervention. Word initially [s] and [l] now appeared in her repertoire. She still hasdifficulties in producing certain consonants in isolation.

The incidence of phonological simplifications in her speech also shows changes,with final consonant deletion, the process specifically addressed in intervention,

Table 6. Comparison of Katy’s speech data at CA 6;5 (pre-intervention) with CA 8;2 (post-intervention)

Assessment CA 6;5 pre-intervention CA 8;2 post-intervention

Severityindices

PCC 22% PCC 49%PVC 74.1% PVC 73.2%PPC 41.9% PPC 58.2%

Phoneticinventory

Word initial position:[m, n, p, b, d, t, k,c, f, w, j, r, ]

Word initial position:[m, n, p, b, d, t, k,c, f, s, w, j, r, l, ]

Word medial position:[m, b, d, t, k, c, w]

Word medial position:[m, n, p, b, d, t,k, c, f, w, l]

Word final position: Word final position:[m n, , p, b, t, d, k, g]

Stimulability All consonants except[v, ð, #, , t#]

All consonants except[v, ð, #, , t#]

Phonologicalprocessesanalysis (% use)

Developmentalprocesses: clusterreduction (100%);final consonantdeletion (96%);prevocalic voicing(40%); stopping offricatives and affricates(21%); gliding (21%)

Developmental processes:cluster reduction (70%);final consonant deletion(54%); prevocalic voicing(12%); stopping of fricativesand affricates (20%);gliding (21%)

Non-developmentalprocesses: voweldistortion (25%)

Non-developmentalprocesses: voweldistortion (25%)

Single wordspeech sample

[bæ] for BAG [bæg] for BAG

[we] for WEB [web] for WEB

[vI] for FISH [vI] for FISH

[gI"me] for CHRISTMAS [gI"me] for CHRISTMAS

[bæ] for PRAM [pæm] for PRAM

[e] for EGGS [e] for EGGS

[bI] for BEES [bI] for BEES

Connectedspeech sample

[k: le: "ab ua ] forHER LEG WAS

BROKEN

[daI n d nu: du: f : ak:]for TRY ON THE NEW

SHOE FOR HER

[a l l taI "a g u]for A LONG LONG

TIME AGO

[ai: bi: "dI.t a aa li:d]

for HE BE SITTING

ON A LEAD

[I "bet na] for ITS

BETTER NOW

[ai: "raIaI a :t] forHE’S RIDING A HORSE

[aaI aæ "peItapi:a "wedI] for I HAD

PLAYTIME ALREADY

[aI "g aI "a v fe:] forHE’S GOING OVER

THE FENCE

[I "pw .bi "dIataI na] for ITS

PROBABLY DINNER

TIME NOW

[dI f :n dau de ] forSHE FELL DOWN

THE STAIRS


reduced from 96% to 54%. Cluster reduction was reduced from 100% to 70%, withKaty now frequently attempting to produce both elements of the cluster (e.g. [bwId]for BRIDGE and [pweIn] for PLANE). /s/ + stop clusters remained challenging for her,for example [dep] produced for STEP. Pre-vocalic voicing was decreased from 40%to 12% whereas Katy’s stopping of fricatives and affricates had decreased minimally.

Discussion

This paper aimed to determine if psycholinguistically-based phonological therapycould lead to (a) specific and (b) generalized improvements in the speech productionof Katy, a child with severe and persisting difficulties. Results from the microevaluation showed significant improvements in Katy’s speech – as well as other areassuch as spelling and auditory discrimination between real words. Katy’s response tothe intervention programme is summarized in table 7, which returns to the specificquestions posed earlier.

Single word speech

In terms of speech at the single word level, the following questions were asked: Willphase I intervention result in an increased count of final consonants in the treatedword lists (A and B)? Will exposure to orthographic forms promote faster learning,

Table 7. Questions addressed by the intervention programme

Area Question Answers

Single wordspeech

Will phase I intervention result in an increased count offinal consonants in the treated word lists (A and B)?

yes

After intervention phases I and II, will Katy’s finalconsonant count (FCC) for list C (untreated controls)also improve beyond chance level?

yes

Will exposure to orthographic forms promote faster learning,i.e. after phase I will list A (speech and spelling treatment)show more improvement than list B (speech only treatment)?

no

Connectedspeech

Will Katy’s FCC for target words used in a short carrierphrase improve in phase I and II, as Katy’s speech processingsystem is modified?

no

Phase III specifically addresses connected speech. Will it resultin significantly increased FCCs in connected speechproductions in the treatment lists A and B?

yes

After intervention phase III, will Katy’s FCC for list C items(untreated controls) in connected speech also improvebeyond chance level?

yes

Spelling Will Katy’s ability to indicate final segments in spelling improvefollowing three phases of intervention for speech?

yes

Auditorydiscrimination

Will improved speech production result in improved abilityto discriminate between treatment stimuli andphonetically similar words?

yes

Will increased experience with production of final consonantsresult in improved discrimination of novel words that differin terms of final segments?

no


i.e. after phase I will list A (speech and spelling treatment) show more improvementthan list B (speech only treatment)? After intervention phases I and II, will Katy’sfinal consonant count (FCC) for list C (untreated controls) also improve beyondchance level?

After the first phase of intervention, Katy’s use of final consonants in singlewords increased significantly not only for the treatment lists but also for theuntreated, matched control set. This suggests that generalized change had beenbrought about, rather than being limited to the specific items that she had beenintroduced to in the intervention. Intervention phase I offered different treatmentsfor the stimuli lists A and B, with A items being given a treatment that explicitlyutilised written forms to promote speech, and B items focusing solely on speech.There was no significant difference in the outcomes from these two differenttreatments. This result is surprising given the theoretical argument that spellingought to promote speech (e.g. Foorman, Francis, Novy and Liberman 1991, Gillon2002), and also in terms of the initial identification of Katy’s strengths that includedawareness of written forms. It has been noted that as a non-word reading task wasnot administered, Katy may have been utilizing a whole word reading strategyor visual memorization to recognize the words rather than decoding per se.Her apparent orthographic knowledge may not be phonologically-based, i.e. shemay be at a logographic stage of reading and lacking the phonological base thatwould support speech development. Stackhouse and Wells (1997) link theirdevelopmental phase model with Frith’s (1985) model of literacy development(figure 9).

It has been suggested that Katy was in the whole-word phase of speechdevelopment at the start of the intervention. This is consistent with her literacydevelopment being at the logographic stage. Katy progressed to the systematicsimplification phase of speech development, but has yet to master the skills of theassembly and metaphonological phases of speech development before she will havethe skills associated with Frith’s alphabetic literacy stage.

After the second phase of intervention, further significant gains were made insingle word speech production. Again, this change was not limited to the treatmentlists but also for the untreated, matched control sets suggesting that generalizedchange had been brought about. Following the third phase of intervention, whichfocused on connected speech, Katy showed a decrease in her production of CVCstimuli in single word naming tasks. This decrease may be attributable to the focusof the intervention in each of the phases: phase I and II focused on single wordproduction and had an effect at this level for each of the three matched stimuli lists.Phase III involved work on connected speech only: no work was done directly onsingle word production. The single word task may have been perceived by Katy asless important than tasks involving connected speech. On the other hand, a recencyeffect may have been acting so that at each post-intervention assessment Katyperformed well on whatever had been addressed most recently in the precedingintervention, but these gains were not maintained in the longer term. However, datafrom T5 (long-term follow-up) suggests that a recency effect was not operating:Gains in connected speech were maintained after intervention ceased, and thedecline in her single word speech production did not continue, a slight increase inperformance being noted at T5.

It is clear that Katy made significant gains in her speech production at the microlevel. Results from the macro evaluation were less clear-cut. The speech assessments


(e.g. Word-finding Vocabulary Test, Renfrew 1995, Edinburgh Articulation Test,Anthony et al. 1971) used at level G of the speech processing profile, showed thatKaty had not improved in relation to her peers. However, more sensitive measuressuch as speech severity indices revealed that significant improvements had beenmade in Katy’s PCC and PPC. Her final consonant deletion had decreased and herphonetic inventory for the word-final position had increased.

The lack of improvement at the macro level suggests that her motorprogramming difficulties, targeted in intervention, are a core deficit in her speechprocessing system. The notions of whole-word phonology and phonotactic therapy(Velleman and Vihman 2002, Velleman 2002) were central to this intervention. Theymay account to some extent for the specific speech improvements noted at a microlevel, and not at the macro level. Intervention aimed to establish a new phonotacticframe in Katy’s motor programming system – and this succeeded; but interventionto date has not focused on the full and accurate specification of the final consonantwithin the template. In terms of the developmental phase model (Stackhouse andWells 1997, 2001) Katy’s speech is now more characteristic of the systematicsimplification phase, having been helped to progress from the earlier whole wordphase. If systemic simplifications (notably stopping) can be addressed in futureintervention, more global changes in her speech may be observed.

Figure 9. The relationship between the phases of speech and literacy development: Developmentalmodel for speech and literacy (from Stackhouse and Wells 1997; Frith 1985).


Connected speech

Relating the findings from the new speech processing profile (figure 8) to thespeech-processing model (Stackhouse and Wells 1997) enables us to reconsider thetheory underlying Katy’s intervention. It was asked: Will Katy’s final consonantcount for target words used in a short carrier phrase improve in phase I and II, asKaty’s speech processing system is modified? Katy was not able to makeimprovement in her connected speech until phase III when connected speechwas specifically addressed. In terms of the speech processing model, the first twophases of intervention focused on motor programmes, while the third phase wastargeting motor planning. For Katy, and possibly for other similar children,generalization of single words into connected speech may be dependent on thespecific targeting of motor planning. The intervention in phase III was verysuccessful in getting her to use the CVC stimuli in sentences, something which shehad been completely unable to achieve before. It is likely that Katy’s attention hadshifted to the production of larger units of speech which involve motor planning,rather than being focused at the single word level.

Again, this change was not limited to the treatment lists but also extended to theuntreated, matched control lists suggesting that generalized change had beenbrought about. Gains made with connected speech were maintained in the long-term, after a period of no intervention, when T4 and T5 performances werecompared. It seems that improvement in connected speech was only brought aboutby specifically addressing connected speech in a carefully structured way. Animportant question to consider in future research is whether the single wordintervention phases were necessary prior to the connected speech phase, or whetherintervention might have started with the connected speech work.

Spelling

It was asked if Katy’s ability to indicate final segments in spelling would improvefollowing three phases of intervention for speech. Katy’s spelling did improvesignificantly, even though the specific incorporation of literacy in Phase I did notseem to have particular benefits for her speech. It may be that in therapy, the effectsof working on speech and spelling are uni-directional: working on speech improvesspelling, but working on spelling does not necessarily improve speech. Alternatively,there may have been no difference between the progress made on the two stimulilists because the inclusion of spelling – albeit only for one of the wordlists – wassufficient to highlight phonological awareness for Katy and have resulting influenceon the other list.

Given that Katy was being exposed to new words and literacy teaching overthe course of the intervention project, it may not seem surprising that her spel-ling skills improved over the intervention period. Pre-intervention assessment ofKaty’s spelling using the Schonell spelling test from the Aston Index (Newtonand Thompson 1982) revealed a spelling age of 5;9 years. One year later oncompletion of intervention, Katy’s spelling age was 6;10 years. This suggests that herspelling skills had not increased more than one might expect given the amount oftime that had elapsed. Therefore her improvements in spelling of the microassessment stimuli can not be regarded as specific and due to the effects of theintervention.


Auditory discrimination

For auditory discrimination it was asked: Will improved speech production result inimproved ability to discriminate between treatment stimuli and phonetically similarwords? Will increased experience with production of final consonants result inimproved discrimination of novel words that differ in terms of final segments? Katyimproved at both the micro and macro level in her ability to discriminate betweenreal words.

How does this improvement relate to the theory of Bishop et al. (1990)suggesting that children with motor output problems are likely to experienceauditory discrimination difficulties secondary to these output difficulties? Katy mayhave made sufficient improvement in her speech to bring about changes in herauditory discrimination. However, the fact that she improved in her real worddiscrimination and not in her non-word discrimination suggests that this is not thecase and that there may be other mechanisms at play. Real word discrimination wasnot directly addressed in the intervention, but Katy’s real word discrimination abilitywas re-assessed several times between the intervention phases. She may haveimproved in this area due to the exposure and practice afforded by the re-assessments. The fact that she improved in her real word discrimination but not inher ability to discriminate between non-words (at even a micro level) suggests thatthese are distinct abilities using different processing routes. Phonologicalrepresentations are tapped by real word auditory discrimination tasks, where top-down knowledge can be used. Phonological recognition is tapped into in non-wordauditory discrimination tasks which rely on bottom-up processing. The fact thatKaty improved in her real word auditory discrimination and not in her non-worddiscrimination suggests that her ability to map from phonological recognition to herphonological representations had improved so that she was now able to use this top-down processing route more effectively.

Clinical implications

Speech and language therapy often focuses on children’s production of specificspeech sounds or production of single words (e.g. Forrest, Elbert and Dinnsen 2000,Williams 2000, Barlow and Gierut 2002). Some children are able to apply whatthey have learnt at a segmental or whole-word level to conversational speech(Wright, Shelton and Arndt 1969, Elbert, Dinnsen, Swartzlander and Chin 1990,Almost and Rosenbaum 1998). However, this is not always the case, and there islittle research addressing the relationship between connected speech and singleword speech production in intervention. Connected speech has importantimplications from a functional point of view and in terms of intervention efficiency.It is important to identify which children will generalize automatically to connectedspeech, and which children will not. This may depend on severity, age, theunderlying nature of the speech processing system or the particular phono-logical processes involved. One child, Zoe, described by Stackhouse and Wells(1993) had severe speech difficulties but was able to generalize from singlewords to connected speech. This child did not have final consonant deletion,and it may be that this process makes children vulnerable in terms of limitedgeneralization.


Conclusion

Katy’s intervention was effective in improving her speech production at the singleword and connected speech level by reducing the frequency of final consonantdeletion and increasing her percentage of consonants correct. However, there aretwo important caveats to note. Firstly, the study is limited to one child and resultscannot be generalized to other similar children. The findings from this study need tobe viewed in conjunction with related case study interventions such as those carriedout by Bryan and Howard (1992) and Ebbels (2000), and the expanding body ofintervention research carried out using psycholinguistic frameworks such asStackhouse and Wells’ (e.g. Constable et al. 1997, Waters et al. 1998, Dent 2001).

Secondly, one needs to consider the different levels of change that were broughtabout in Katy’s speech processing system. The micro evaluation considered specificchanges in the treated and untreated (but carefully matched) stimuli. The macroevaluation aimed to provide evidence of any global changes in her speech processingsystem. The results at each of these levels are summarised in table 8.

One needs to consider both macro and micro levels of change in order to gain afull understanding of the outcomes achieved. We need to consider the two levels ofchange as closely interlinked. Ongoing and intensive intervention brings aboutmicro changes that may eventually result in macro changes. The present study aimedto evaluate the effectiveness of a particular intervention. The design of theintervention does not allow for comparisons with other approaches to intervention:we do not know if other approaches to intervention would have been more or lesseffective. It is for this reason that further detailed intervention studies includingwide-ranging outcomes measures are required. However, this present approachoffers an explicit framework for understanding intervention studies and interpretingthe results, drawing on psycholinguistic and phonological theory.

Recent randomized control studies (Glogowska et al. 2000) have seemed to showthat interventions for children with speech and language impairments do not work.However, in evaluating such studies we need to consider the dosage and nature oftherapy that is given. Clearly, in the case of children with severe, specific andpersisting speech difficulties, intervention can be successful when the intervention isspecific and intensive. The case presented here provides evidence of the value ofdirect and specific intervention for a child with severely disordered speech. Law andConti-Ramsden (2000) urge practitioners and managers to offer a more flexiblepackage of interventions, suggesting that the results of a body of evidence-based

Table 8. Changes in Katy’s speech processing system using two levels of evaluation

Micro evaluation* Macro evaluation**

Speech ! !Spelling ! XAuditory discrimination

Real words ! !Non-words X X

!, Significant (p,0.05) change noted; X, no change noted.*Stimuli shown in table 4 and the appendix**Based on severity measures for speech (table 6); standardized test results for spelling (table 3) andauditory discrimination (figure 8).


practice should be acted upon. Studies such as the one presented here contribute tothat body of evidence.

Acknowledgements

The authors thank Katy, her family and teachers for participating in the study.Thanks to the local Speech and Language Therapy Agency for support with thiswork. This case study formed part of the first author’s PhD research, which wasfunded by the Overseas Research Students Award Scheme, and studentships fromthe University of Sheffield, UK and University of Cape Town, South Africa.

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Appendix

Qualitative changes in Katy’s single-word speech production

StimulusT1

Pre-intervention T2 T3 T4T5

Follow-up

List A: treated words 1 NOTE n u n ut n ut n ut n ut2 PLANE peI peIn pen pweI plem3 HEART a ha hat at hat4 NAIL neI. neI.j ni.j neI. neI.j5 CAGE keI keI keIt keIt keIk6 SLIDE daI taIt tsaId taIt daId7 WHEEL wi. wi. wi. wi. wi.j8 RAKE reI jeIk weIk weIk weI

9 STORK d .g t k t k d k d k10 LEAF jif lI liv lif ji11 SAUCE d d d d d12 ICE aI aI aIt aI aIt13 SOAP d d up d up d u d up14 PIPE paI baIp paIp paI paIp15 BARN ba ba ban ban ban16 ROAD w w w uv w u w ud

List B: treated words 1 BOAT b b ud b ud b ut b ut2 RAIN weI weIt reIn weIn weIn3 CART ka kat kat ka ka4 WHALE weI. weI.j wI. l weI. weI

5 AGE eI eI eId eId eI

6 HIDE aI aIt eId aI aI

7 SEAL si dI. si. di. si.j8 CAKE keI jeIk keIk keIk keIk9 FORK f f f k f f k

10 HALF a a af a af11 FLEECE fi fIt fit fwi fIt12 SLICE daI tslaIt saI daI daIt13 ROPE w w up w up w up w up14 PEEP pi pIp pIk pIp bIp15 DAWN d d d n d u d n16 SWORD d d d d d d s d

List C: untreatedwords

1 GOAT g u k ut g ut g ut g u2 TRAIN teI teI teI t#eI teIn3 PART ba pa pat ba ba4 HAIL eI. eI.j eI.Il eI. eI.j5 PAGE peI bed peId beI beIt6 LIED laI jaI laId laIf jaId7 KNEEL ni nij ni. ni. ni.8 STEAK deI teI steIk deIk deIk9 WALK w w g w k w k w k

10 HOOF u uf huf uf uf11 PURSE bk pk pk pkt pkd12 DICE daI daI daI daI. daIt13 GRAPE keI geI geIp geIp geIp14 SHEEP i ti sip #ip sIp15 LINE jaIn jaI laIn laI jaIn16 TOAD t u t u t ud d u d u

220 Phonological therapy within a psycholinguistic framework

phonological therapy within a psycholinguistic framework

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