Kinematic modeling and acoustic measures of breathy voice.

Abstract

A variety of disordered vocal fold structural and vibratory parameters have been identified in patients with breathy dysphonia, although the contribution of each parameter to voice quality is unknown. This study is part of an effort to determine the relation between production and voice quality. A kinematic vocal fold model [based on I. R. Titze, Speech Commun., 8, 191–201 (1989)] that emulates the medial surface of the vocal folds was used to ascertain factors that lead to breathy voice. Based on the ratings of four expert listeners, five parameters were selected for further study. Combinations of multiple levels of adduction, bulging, nodal point, epilaryngeal area, and phase were used to generate 180 samples of sustained /ɑ/ and /ɪ/. Seven acoustic analyses were performed for each sample: maximum flow declination rate, maximum area declination rate, two measures of H1-H2, two measures of cepstral peak prominence, and noise to harmonics ratio. All parameters led to systematic changes in acoustic measures reflecting increasing breathiness, with several inconsistencies highlighting the uniqueness of each measure. The H1-H2 measures were inconsistent with the other data. Results will be described in light of how each measure can inform researchers about production. [Work supported in part by NIH R01-DC04789.]