Rudolph Sock
Anders Lofqvist
Haskins Labs., 270 Crown St., New Haven, CT 06511-6695
Inst. de la Commun. Parlee, Univ. Stendahl, BP 25 X, 38040 Grenoble, France
The timing of lip and jaw movements and acoustic events was studied in one subject producing the six pseudowords /pipi,papa,pupu,bibi,baba,bubu/ at two speaking rates. Lip and jaw movements were recorded optoelectrically. Acoustic durations of bilabial closures served as a temporal base for analyzing consonantal resistance to vowel coarticulation. Within each temporal base, a phase was defined as the interval between peak raising or lowering velocity of an articulator and the acoustic onset of the following vowel. The proportion of time taken by each phase in the temporal base provides a measure of anticipatory coarticulation of the vowel in the consonant. Results suggest that the rounded vowel /u/ has a higher coarticulatory influence on the labial consonant that the unrounded vowels. The voiced consonant /b/ has less resistance to coarticulation than its unvoiced cognate. Both domains investigated show comparable phasing patterns, suggesting a general strategy of coarticulation for the successive consonants. Generally, all three articulators show similar gestural kinematic patterns. The results are discussed in terms of biomechanical constraints on speech production tightly coupled with the perceptual requirements of the linguistic code. [Work supported by the Fyssen Foundation and NIH.]