Patterns of correlation of tongue movement and electromyographic signal in vowel production.

Abstract

X-ray microbeam data from pellets on the jaw, tongue, and lips were compared with EMG signals from eight muscles for production of multiple tokens of 11 vowels in /schwapVp/ context, for an American English speaker. Pellet data were obtained from the Tokyo x-ray microbeam while electromyographic data were obtained at Haskins Laboratories. Acoustic recordings and a comparison of orbicularis oris electromyographic records with lip pellet movement data were used to link the two data sets, so that an estimate of muscle contraction time could be made and appropriate correlations of time functions across the sets generated. Tongue pellet data were adjusted to compensate for the effects of jaw position. Relations between EMG and movement signals for the point vowels /i/, /open aye/, and /u/ were as expected, in that movements up and front were accompanied by large signals from anterior and posterior genioglossus, movements up and back were accompanied by large signals from styloglossus, while tongue lowering movements were accompanied by substantial hyoglossus signals. However, relations among muscle signals were unique to each vowel. [Work supported by NIDCD grants to Haskins Laboratories.]