Simultaneous cineradiographic-electromyographic-acoustic analysis of vowel production

Abstract

In an x-ray study of vowel production, three types of measurements, namely articulator movement, EMG, and acoustic, were simultaneously made as a single subject produced various vowels in a ∂pVp environment. Movement measurements were obtained from the lips, tongue, jaw, and velum. EMG signals were collected from a single lip muscle, the Orbicularis Oris, and from two tongue muscles, the Genioglossus and Superior Longitudinal. Formant frequencies and amplitude measures were extracted from the audio signals. The subject's vowel space was plotted for each of these three types of measures. For the tongue, jaw, and lip, amplitude and timing relationships among movement, EMG, and acoustic signals were analyzed. Movement measurements indicated minimal jaw movement. The tense-lax vowel distinction was characterized by differences in articulator position, EMG amplitude, formant frequency, acoustic amplitude, and vowel duration. Relative timing of vowel (tongue) and prevocalic consonant (lip) activities was also analyzed for each of the three types of measures. The onsets of vertical tongue dorsum activity were closely associated with the timing of the lip gesture. However, horizontal tongue dorsum activity for back vowels began much earlier than the lip gesture. [Work supported by NINCDS and BRSG grants.]