Fluid dynamics measurements during phonation

Abstract

Fluid dynamic properties of air within the larynx changes so rapidly during phonation that its measurement could be a challenge for voice research. These measurements included time varying glottal pressure and air particle velocity in narrow passages that pose many technical difficulties. In this paper, to elucidate these challenges, measurement of dynamic pressure acting on the vocal folds in a canine hemilarynx model has been initially examined. Then static and dynamic volume flow measurements and, finally, the particle velocity measurements with hot‐wire anemometry within the glottal jet have been discussed. Canine excised larynges as well as canine hemilarynges were used as phonation models. For dynamic pressure measurements, miniature pressure transducers were embedded in a Plexiglas plate that replaced one vocal fold and recorded the oscillation pressure. All mounted laryngeal models were subjected to increasing pressure‐flow sweeps at various adduction levels and the measured data was processed for dynamic pressure and velocity profiles. Results indicated that pressure within the glottis vary both vertically and longitudinally during each vibratory cycle. The pressure signals close to the superior edge showed large negative values due to the motion of the vocal folds. [Work supported by NIDCD Grant No. DC03566.]