ASA 126th Meeting Denver 1993 October 4-8

1pSP3. Phonation threshold pressure in a physical model of the vocal folds.

Ingo R. Titze Michael R. Titze

Natl. Ctr. for Voice and Speech, Dept. of Speech Pathol. and Audiol., Univ. of Iowa, Iowa City, IA 52242

A physical model of a vocal fold was constructed with three layers: an artificial epithelium (latex), a superficial Reinke's space (water), and an immobile vocal fold body (aluminum). This vocal fold was positioned in a plexiglas airway such that the glottal aperture and the convergence angle could be varied systematically with respect to a solid boundary, which represented the opposite vocal fold in a hemilarynx configuration. Subglottal pressure was controlled with a constant pressure valving system. Phonation threshold pressure (the Hopf bifurcation in nonlinear dynamics) was measured as a function of glottal aperture and divergence angle. This pressure increases with increased aperture and convergence, as predicted by theory, but results for a divergent glottis are not as easy to interpret. [This research was supported by Grant No. P60 DC00976 from the National Institute on Deafness and Other Communication Disorders.]