Kinematics of Lip and Jaw Closing Movements during Bilabial Stop Consonant Production: Effects of Utterance Length and Word Position

This study is part of a larger project investigating the individual and combined effects of word position, utterance length, and phonetic context on kinematic aspects of labial and mandibular movements during grammatically correct and semantically meaningful utterances. In the present study, the effects of word position and utterance length on kinematic measures of movement duration, movement extent, peak velocity, and time to peak velocity during bilabial closing gestures for the stop consonants /p/ and /b/ were examined. Analyses revealed no statistically significant effect of word position. Utterance length, on the other hand, had a statistically significant effect on most of the dependent variables under investigation. Such effects were observed in the kinematic signals associated with movements of the individual articulators (upper lip, lower lip, or jaw) as well as in a mathematically derived signal of lip aperture.