Glottal pressure profiles for a diameter of 0.04 cm

Abstract

Computer models of phonation often rely on aerodynamic equations for flow through the glottis. Usually the aerodynamic equations have come from empirical work with steady-flow models made from hard material. The equations simplify the pressure-flow-geometry relations through the larynx. The model used here (model M5) has 14 pressure taps on the vocal folds to give rather complete pressure profiles. Pressure profiles will be reported for symmetric glottal shapes, a minimal diameter of 0.04 cm, and nine glottal angles (uniform; convergent, and divergent 5, 10, 20, and 40 deg) for transglottal pressures of 3, 5, 10, and 15 cm H2O. The glottis is rectangular in the anterior–posterior direction, with a glottal length of 1.2 cm. Results indicated that the pressure coefficient for the glottal entrance ranged from 1.09 to 1.60 with an average of 1.33 (compared to van den Berg’s 1.375). The value decreased as flow increased for any specific glottal angle. The transglottal pressure coefficient ranged from 1.00 to 1.82 with an average of 1.28. The average value for the uniform glottis was 1.63. Values decreased as flow increased. Pressure profiles will be compared to predictions from current glottal aerodynamic equations. [Work supported by NIH Grant 1R01DC03577.]

The effect of three-dimensional glottal geometry on intraglottal quasi-steady flow distributions and their relationship with phonation

“…Several previous studies have motivated the use of the chosen glottal geometry in this study [3][4][5][6]1) , but they have not examined in detail the flow distributions for a wide range of glottal shapes in a more three-dimensional model. The purpose of this study was to quantify the pressure and velocity distributions in a physical glottal model when the glottis takes on different convergent, uniform, and divergent shapes, to better understand the aerodynamics of phonation.…”