Luc Mongeau: "Biomechanics of Voice Production"

Luc Mongeau is Professor in the Department of Mechanical Engineering, McGill University

ABSTRACT:
The influence of a posterior gap on the airflow through the human glottis was investigated using a driven physical model having a converging coronal-planar profile.  Instantaneous orifice discharge coefficients of the model were obtained from the time-varying orifice area and the velocity distribution of the pulsated glottal jet measured on the axial plane using a single hot-wire probe.  Sound pressures were also measured to characterize the influence of the minimum flow through the posterior gap on the radiated sound.  A cyclic hysteresis of the orifice discharge coefficients was observed, which indicated a pressure head increase and a net energy transfer from the air flow to the orifice wall.  A comparison between radiated sound pressure levels for the cases with and without the posterior gap showed that the presence of the minimal flow increased the broadband sound level produced over the frequency range in which human hearing is most sensitive.  The impact of these findings on voice production will be discussed.  An overview of other ongoing research projects on the mechanics of the vocal folds will also be described.