Intrinsic velocity differences of lip and jaw movements: preliminary results

The observed kinematics of speech movements are the result of both the control by the brain and the biomechanical properties of the peripheral speech apparatus. For many kinematic phenomena, it is not clear whether they are actively controlled or intrinsic to the biomechanical system. This pilot study investigated the movement of sensors on the lips and the jaw in cyclical vowel transitions at specific speaking rates to identify possible intrinsic differences in the velocities of the articulators. Thereby, the lower lip was found to be significantly faster in approaching its targets than the upper lip, the mouth corners, and the jaw. Furthermore, for the mouth corners, backward movements were significantly faster than forward movements.