Glottal geometry and phonation threshold pressure in a vocal fold physical model.
Roger W. Chan, Ingo R. Titze, Michael R. Titze · The Journal of the Acoustical Society of America · 1996
The effect of convergent and divergent prephonatory glottal geometries on phonation threshold pressure was investigated using a previously reported physical model of the vocal fold mucosa [Titze et al., J. Acoust. Soc. Am. 97, 3080–3084 (1995)]. Lowest offset phonation threshold pressure in the range of 0.07 to 0.23 kPa was obtained for a rectangular or a near-rectangular glottis (with convergent or divergent angle ≤3°) across different glottal half-widths between 2.0 and 6.0 mm. Phonation threshold pressure for more convergent or divergent glottal geometries was consistently higher. This finding only partially agrees with previous analytical work which predicts a lowest phonation threshold pressure for a divergent glottis [I. R. Titze, J. Acoust. Soc. Am. 83, 1536–1552 (1988) and J. C. Lucero, J. Acoust. Soc. Am. 98, 779–784 (1995)]. The discrepancy between theory and data is likely to be associated with flow separation from a divergent glottis. [Work supported by NIH.]