Experiments concerningboundary tone perception in German3rd Workshop of the SPP-1234

Potsdam, 7th January 2009

Presentation of the Stuttgart Project (Möbius & Dogil)

Katrin Schneider

Outline

Categorical Perception (CP) Perceptual Magnet Effect (PME) Experimental designs Stimulus preparation Experiments:

Boundary tone perception in German without context information

Boundary tone perception in German including context information (Identification only)

Outlook

Categorical Perception (CP)

Test design developed according to the perception of plosives (Repp, 1984) Perception is categorical if the peak in discrimination

corresponds to the category crossover found in identification.

Experiments in the prosodic research area: House (1996) Kohler (1987, 1990) Ladd & Morton (1997) Remijsen & van Heuven (1999); van Heuven & Kirsner

(2004) Schneider & Lintfert (2003) Falé & Hub Faria (2006)

Perceptual Magnet Effect (PME) Kuhl (1991):

Phonetic perception is influenced by language experience

PME: discrimination ability differs inside a category prototype (P) attracts its immediate neighbors – low

discrimination performance around a non–prototype (NP) – better discrimination

performance

Experimental designs

Testing for CP and PME simultaneously Identification: assign stimulus to one of the given

categories Goodness rating (only for PME):

separately for each category found in identification How well does the presented stimulus fits into the assigned

category? scale given Discrimination:

Does the presented stimulus pair consists of identical or of different stimuli?

differences in the construction of stimulus pairs between CP and PME test design

Stimulus preparation

Test for German boundary tones (BT) Test stimulus:

ambiguous between statement/question interpretation no syntactic bias: PP

noun consisting of mostly sonorants; no /ə/ pitch accent not on the last syllable polysyllabic noun; no compound noun

“ins kalte Panama” (in the cold Panama), embedded in carrier sentences

male native German speaker

Stimulus preparation

Manipulation of fundamental frequency (F0) of the last 2 syllables of the target PP: Calculation F0 range: mean rise to H%: 90 Hz; mean

fall to L% : 50 Hz ERB (Equivalent Rectangular Bandwidth) scale used PSOLA resynthesis

Headphones used during each test

H*L

Additional stimuli for PME test

Additional stimuli for PME testH%

L%

0,338ERB

Perception of German boundary tones (without context) Results (25 subjects (10 females)):

s-shaped curves in identification; 2 categories CP and PME for the statement category:

clear prototype & non-prototype (goodness rating) disc. peak & warping of perceptual space around P

unclear results for the question category: better within-category discrimination performance than in

statement category → no clear CP, but also no gradual perception

individual prototypes differ → no PME problematic: combination of CP and PME test design

in discrimination

Perceptual reference space

Perception of German boundary tones (including context information) Why?

context might have an influence on the location of the category boundary

there is always context in normal conversation – no “out-of-the-blue” sentences

How? 2 different context types we tested for:

BT height of the preceding sentence (influence of F0)) syntactic structure of the preceding sentence (influence of

syntax) same speaker as in previous experiment

Contexts: fundamental frequency (F0)

Does the F0 of the preceding sentence influences perception? preceding sentences: statement vs. question; only

difference in BT heighta)

“Er will verreisen. Nach Panama./?”

b)

“Er will verreisen? Nach Panama./?”

L%

Time (s)

0 3.04219

0

250

Time (s)

0 3.04219

0

250

L%

H%

Time (s)

0 3.04219

0

250

L%

H%

Time (s)

0.00980033 1.67695

0

250

H%

L% condition

H% condition

Contexts: syntax

Does the syntactic structure of the preceding sentence influences perception? preceding sentences: synt. statement vs. synt. question;

differ in their syntactical constructions

a)

“Er will verreisen. Nach Panama./?”

c)

“Was liegt da? Ein Ticket nach Panama./?”

L%

Time (s)

0 3.04219

0

250

Time (s)

0 3.04219

0

250

L%

H%

Time (s)

0 3.18356

0

250

L%Time (s)

0 3.18356

0

250

L%

H%

L% condition

Wh_L% condition

Identification

20 stimuli in each condition; 10 repetitions = 600 stimuli; randomized order

3 subtests: each incl. 6 training stimuli & 200 test stimuli 36 participants (23 females, 13 males) Exclusion of high reaction times (RT):

outliers > 2*sdev+mean RT outliers > 2,374614 2,5% of the data

excluded

Identification: general results Results:

clear s-shaped curves for all contexts

L%H%Wh_L%

Identification: general results Results:

clear s-shaped curves for all contexts

significant differences inside the BT-height

condition as well as inside the

syntax condition there seems to be an

influence on the location of the category boundary in each context condition in the intended direction

Identification: gender differences Gender differences:

in each single context condition as well as pooled over all data, females: show an earlier

crossover than males

pooled over all contextscondition L%condition H%condition Wh_L%

Identification: gender differences Gender differences:

in each single context condition as well as pooled over all data, females: show an earlier

crossover than males are significantly faster

than males

pooled over all contextscondition L%condition H%condition Wh_L%

Identification: gender differences Gender differences:

in each single context condition as well as pooled over all data, females: show an earlier

crossover than males are significantly faster

than males no sign. differences

inside each category (‘statement’ vs. ‘question’)

Identification: gender differences Differences in context conditions:

males: only BT height influences location of category boundary

L%H%

L%Wh_L%

Identification: gender differences Differences in context conditions:

females: only syntax influences location of category boundary

L%H%

L%Wh_L%

Identification: RT

RT as indicator for category boundary? males: nearly perfect match in all contexts

L% conditionH% conditionWh_L% condition

Identification

RT as indicator for category boundary? females: nearly perfect match (except H% condition)

L% conditionH% conditionWh_L% condition

Summary Identification

significant gender differences with respect to the category boundary location reaction times

significant differences between presented context conditions, however gender of the participant has to be taken into account

Outlook

finish the analyses of this experiment: Goodness rating & CP discrimination: on the poster PME discrimination analysis: currently running Perceptual reference maps & comparison to without-

context results further experiments:

Finish experiment with female voice & compare possible gender-specific behavior to male-voice experiments

Experiments concerning pitch accents (preparation finished) & analyze the results

Thank you!

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