Cross-linguistic Effects in the Perception of Assimilated Speech.
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Transcript of Cross-linguistic Effects in the Perception of Assimilated Speech.
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)
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
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)
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)
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
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
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
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
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
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
Render the nalip shinnow please
caveescaveesh
pidastamash
nalipremop
samalshamalsivalshinnowpagoonpentuf
Experimental Designobjects buttons
Word 1 Word 2Rendez le nalip
shinnow s’il vous plait
Render the nalip shinnow please
Experimental DesignTask from Pirog Revill et. al 2008
Experimental Design
Render the cavees pagoon please
Testingobjects first
Render the nalip samal please
buttons first
Following context Preceding context
Training
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)
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***
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)
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
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
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
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
Phonetic results
English French
Niehbuhr, Clayards, Meunier, Lancia (in revision)