Gestural timing in naïve listener imitation of Cantonese vowels

Studies of nonnative vowel production have analyzed sounds predominantly in terms of acoustics, while the underlying articulatory gestures, as well as their timing, remain understudied. This study examines nonnative production of backness and rounding contrasts in the Cantonese vowel sets /i y u/ and /ɛ œ ɔ/. 15 native Cantonese speakers and 15 native English speakers participated. Native English speakers read a list of English words containing the vowels [i u ɪ ʊ e o ɛ ɔ], and then imitated Cantonese words containing [i y u ɪ ʊ ɛœ ɵ ɔ], presented auditorily. L1 Cantonese speakers produced the same set of Cantonese words, presented orthographically. Dynamic acoustic, ultrasound, and lip video data were collected and analyzed using GAMMs. In L1 Cantonese, target tongue and lip positions are achieved at vowel onset and maintained throughout the vowel duration, yielding acoustically monophthongal vowels. In contrast, L1 English [u, o] exhibit peak rounding during the vowel offglide, while magnitude of tongue and F2 displacement vary according to consonantal context. Lip gestures show similar late timing in non-native imitations of Cantonese [y, u], yielding English-like F2 trajectories, although the two vowels differed in tongue position. These results suggest that acoustically non-native-like vowel productions may result in part from transfer of L1 gestural timing. [Work supported by Hong Kong RGC, No. 27614421.]