cross-linguistic effects in the perception of assimilated speech

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Cross-linguistic Effects in the Perception of Assimilated Speech

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Page 1: Cross-linguistic Effects in the Perception of Assimilated Speech

Cross-linguistic Effects in the Perception of Assimilated Speech

Page 2: Cross-linguistic Effects in the Perception of Assimilated Speech

Lexical access in speech perception

• Rapid identification: 250-500 ms• Large lexicon: 50,000+ words• Crowded space

– e.g., “cat” has over 25 neighbours differing on the identity of a single phoneme (e.g., rat, cut, cap)

• So, little room for error– Even subphonemic manipulations can affect the

activation of a word (Andruski, Blumstein & Burton, 1993; Davis, Marslen-Wilson & Gaskell, 2002)

Page 3: Cross-linguistic Effects in the Perception of Assimilated Speech

Phonological variation

• Problem of crowded space compounded by natural variation in surface form of speech

• Focus in particular on assimilation of place of articulation:– Changes place of articulation of word-final coronal

consonants to become more like following context• lean bacon leem bacon• dress shop dresh shop

– Crosses word boundaries– Can be a continuum of assimilation

• full assimilation creates strongest ambiguity

Page 4: Cross-linguistic Effects in the Perception of Assimilated Speech

Contextual Viability

• Perceptual system makes use of contextual viability in determining likely underlying sequence– e.g., Gaskell & Marslen-Wilson (1996)

• “Leam bacon” perceived as “Lean bacon” [shared POA]• But “Leam gammon” causes mismatch in perception

[mismatching POA]– Compensation effect observed in a wide range of

circumstances (e.g., Gow, 2001; Mitterer & Blomert, 2003)

Page 5: Cross-linguistic Effects in the Perception of Assimilated Speech

Accounts of compensation

• Models that deal with context effect differ in terms of their reliance on statistical learning– Gow (2002, 2003)

• separate out cues to assimilated consonant using feature parsing• works best for incomplete assimilation• similar perceptual account given by Mitterer & Blomert (2003)• applies to assimilations irrespective of language background

– Gaskell (2003)• learn circumstances of assimilation from statistics of language and

compensate accordingly• applies to both complete and incomplete assimilation• predicts cross-linguistic differences (statistics are tailored to native

language)

Page 6: Cross-linguistic Effects in the Perception of Assimilated Speech

Data on cross-linguistic effects• Some studies found little or no effect of native language on

perception of assimilation– Gow & Im (2004) – Hungarian/Korean/English– Mitterer et al. (2006) – Hungarian/Dutch

• short sequences, simple perceptual tasks

• Others found clear effects of language background– Darcy et al., (2007, in press) – French/English

• longer sentential context, word detection tasks

• Key factor may be the degree to which the full range of utterance processes can be engaged– But with broader sentence context, it becomes harder to control all

aspects of stimuli for two sets of speakers

• Goal of current research: maintain tight control of stimuli while engaging sentential level processing

Page 7: Cross-linguistic Effects in the Perception of Assimilated Speech

General Methodology

• Speakers of two languages learn an artificial lexicon (words refer to abstract objects)– equates lexical knowledge

• During testing, embed same two-word sequences varying on degree of assimilation into sentence contexts using the speaker’s native language– equates sentential context and phonetic properties

• Examine lexical preferences using the visual world eye-tracking paradigm– look of evidence of cross-linguistic differences in highly

comparable circumstances

Page 8: Cross-linguistic Effects in the Perception of Assimilated Speech

Choice of assimilation phenomenon

• Need assimilation that:– shows significant differences in extent or conditions across

two languages– involves consonants that are phonetically similar in the two

languages

• Selected sibilant assimilation in English and French (cf. Holst & Nolan, 1996)– standard view is that English shows strong regressive

alveolar to postalveolar assimilation (e.g., dress shop → dresh shop)

– whereas such assimilation is absent in French

Page 9: Cross-linguistic Effects in the Perception of Assimilated Speech

Phonetic StudyNiehbuhr, Clayards, Meunier, Lancia (in revision)

4 speakers of both languagesMeasured spectral centre of gravity (CoG) and duration

ENGLISH FRENCH

Regressive “See how the glass shines”STRONG

“C’etait une classe chargée”WEAK

Progressive “She likes the British south”ABSENT

“Tu te cache sous le lit”WEAK

Type s sh s sh

Page 10: Cross-linguistic Effects in the Perception of Assimilated Speech

Perceptual study - predictions

ENGLISH FRENCH

Regressive “See how the glass shines”STRONG

“C’etait une classe chargée”WEAK

Progressive “She likes the British south”ABSENT

“Tu te cache sous le lit”WEAK

Type s sh s sh

Language specific contextual compensation should develop in cases where complete assimilation causes ambiguity

Predict cross-linguistic differences in regressive (following context) but not progressive (preceding context) assimilation

Page 11: Cross-linguistic Effects in the Perception of Assimilated Speech

Equate Stimuli• Artificial lexicon• 1 French and 1 English native speaker• Listeners hear both speakers in both languages

Compare complete and partial assimilation• cross-spliced intermediate CoG as well as endpoints

Compare following and preceding context

/ʃ/ /s/ 1 2 3 4 5 6 7

Experimental Design

Page 12: Cross-linguistic Effects in the Perception of Assimilated Speech

Render the nalip shinnow please

caveescaveesh

pidastamash

nalipremop

samalshamalsivalshinnowpagoonpentuf

Experimental Designobjects buttons

Word 1 Word 2Rendez le nalip

shinnow s’il vous plait

Page 13: Cross-linguistic Effects in the Perception of Assimilated Speech

Render the nalip shinnow please

Experimental DesignTask from Pirog Revill et. al 2008

Page 14: Cross-linguistic Effects in the Perception of Assimilated Speech

Experimental Design

Page 15: Cross-linguistic Effects in the Perception of Assimilated Speech

Render the cavees pagoon please

Testingobjects first

Render the nalip samal please

buttons first

Following context Preceding context

Page 16: Cross-linguistic Effects in the Perception of Assimilated Speech

Training

Page 17: Cross-linguistic Effects in the Perception of Assimilated Speech

Inclusion criteria• Participants with more than 25% errors on

endpoints for control condition excluded– Both groups of listeners did better with the French

speaker

– Main analyses run on just data for French speaker (any bias goes against key prediction)

Page 18: Cross-linguistic Effects in the Perception of Assimilated Speech

Mouse click responses (following context)

“Render the cavee...controlshinnow”sival”

/ʃ/1234567

/s/

French speaker only

French listenersEnglish listeners

Stats (logistic mixed effects model): Effect of test context (s vs sh)*Interaction with listener group***

Page 19: Cross-linguistic Effects in the Perception of Assimilated Speech

French listenersEnglish listeners

Mouse click responses (preceding context)

“Render the ...amal”controltamashpidas

/ʃ/1234567

/s/

French speaker onlyStats (logistic mixed effects model): Effect of test context (s vs sh)***

Interaction with listener group (ns)

Page 20: Cross-linguistic Effects in the Perception of Assimilated Speech

Time-course of effects (regressive)

Occulo-motor delay (200 ms)

This spectrogram illustrates the control condition (1 sibilant, 120 ms long)

step step x following context

Time bin 200-300

300-400

400-500

500-600

600-700

700-800

800-900

step * * * * * *

following context * * * *

step x following context * *

following context

English listeners

Page 21: Cross-linguistic Effects in the Perception of Assimilated Speech

Time-course of effects (progressive)

Occulo-motor delay (200 ms)

This spectrogram illustrates one of the test conditions (2 sibilants, 200ms long)

Time bin 200-300

300-400

400-500

500-600

600-700

700-800

800-900

step * * * * * *

preceding context * * *

step

preceding context

French listeners

Page 22: Cross-linguistic Effects in the Perception of Assimilated Speech

Conclusions

• French and English listeners differ in their use of following context in regressive assimilation– English listeners show contextual viability effects across a broad

continuum, including complete assimilations– French listeners show little or no viability effect

• In the progressive case, both sets of listeners use sibilant cues contrastively, with no cross-linguistic difference

• These data suggest that listeners adapt to the ambiguities typical of their language– Complete assimilation in production leads to compensatory perceptual

effects– In other cases, generic feature parsing/compensation for coarticulation

applies

Page 23: Cross-linguistic Effects in the Perception of Assimilated Speech

Thanks to...

• Other members of the Marie Curie Sound to Sense group, especially:– Uli Frauenfelder– Sarah Hawkins– Christine Meunier– Noel Nguyen

• Eyetrackers:– Gerry Altmann and Dirk Kerzel

Page 24: Cross-linguistic Effects in the Perception of Assimilated Speech
Page 25: Cross-linguistic Effects in the Perception of Assimilated Speech

Phonetic results

English French

Niehbuhr, Clayards, Meunier, Lancia (in revision)