Anders Lofqvist
Vincent L. Gracco
Patrick W. Nye
Haskins Labs., 270 Crown St., New Haven, CT 06511-6695
The present study was designed to contribute information on tongue, lip, and jaw movements in sequences of vowel--stop--vowel sounds. The speech material consisted of VCV sequences, with all possible combinations of the vowels /i, a, u/ and the stop consonants /p, t, k/; stress occurred on the second vowel. Receiver coils were attached to the upper lip, lower lip, jaw, tongue tip, and tongue blade; their movements were tracked using an electromagnetic transducing system with three transmitter coils. Results from one speaker suggest the following. When plotted in an occlusal plane reference system, tongue movement trajectories are generally curved. In addition, when the vowels occur in the context of the consonants /t/ and /k/, the tongue trajectories commonly loop back across themselves, thus forming closed loops. Jaw movements showed both curved and linear trajectories for all consonantal contexts. Predictably, tongue movements towards and away from the point of tongue--palate contact showed influences from both the preceding and the following vowel. The temporal and spatial coordination of lip, tongue, and jaw movements in speech production will be discussed. This discussion will focus on the gestures underlying speech motor control and the blending and aggregation of these gestures. [Work supported by NIH.]