Entrance loss coefficients and exit coefficients for a physical model of the glottis with convergent angles.

Pressure distributions were obtained for 5°, 10°, and 20° convergent angles with a static physical model (M5) of the glottis. Measurements were made for minimal glottal diameters from d = 0.005-0.32 cm with a range of transglottal pressures of interest for phonation. Entrance loss coefficients were calculated at the glottal entrance for each minimal diameter and transglottal pressure to measure how far the flows in this region deviate from Bernoulli flow. Exit coefficients were also calculated to determine the presence and magnitude of pressure recovery near the glottal exit. The entrance loss coefficients for the three convergent angles vary from values near 2.3-3.4 for d = 0.005 cm to values near 0.6 for d = 0.32 cm. These coefficients extend the tables of entrance loss and exit coefficients obtained for the uniform glottis according to Fulcher, Scherer, and Powell [J. Acoust. Soc. Am. 129, 1548-1553 (2011)].