In this talk, I will report on our recent work which seeks to advance our understanding of the temporal extent of anticipatory coarticulation, its cross-linguistic variation, and its variation between individuals of the same language community. Some studies have linked language-specific variation in coarticulation to phonological contrast (e.g., Manuel, 1990), yet the evidence for this has been equivocal (Scarborough et al. 2015). Moreover, it is not well understood how language specific effects relate to variability in coarticulation between individual speakers. For instance, Noiray et al. (2011) in a study on anticipatory lip rounding in English and Canadian French found no evidence of systematic patterns by language, despite French, but not English contrasting rounding on vowels. They therefore concluded that the implementation of anticipatory lip rounding is speaker-dependent, rather than language specific.
We have undertaken a large-scale comparative study on contextual vowel nasalization as well as lip rounding in three languages. We recorded nasalance and ‘blue lip’ video data (Lallouache 1991) for French, German, and American English for 27-30 speakers per language. For English, neither nasality nor rounding is contrastive for vowels, for French, both are contrastive whereas German contrasts lip rounding only. This allows us to study, for the same speakers, the coarticulatory behavior for two independent articulators, in the presence or absence of a phonological contrast (across languages). Our results confirm the presence of language-specific effects for both articulators, despite a considerable range of individual variation within each language. Contrast possibly serves to constrain the between-speaker variability rather than the temporal extent of coarticulation. Notably in all three languages, the temporal extent of coarticulation exceeds what current theories of coarticulation allow us to predict.
References
Lallouache, M. T. (1991). Un poste « Visage-parole » couleur. Acquisition et traitement automatique des contours des lèvres. PhD thesis, Institut National Polytechnique de Grenoble.
Manuel, S. (1990), The role of contrast in limiting vowel-to-vowel coarticulation in different languages. Journal of the Acoustical Society of America, 88(3): p. 1286-1298.
Scarborough, R., G. Zellou, A. Mirzayan and D.S. Rood (2015). Phonetic and phonological patterns of nasality in Lakota vowels. Journal of the International Phonetic Association. 45(3): p. 289-309.