Topical Problems of Fluid Mechanics


Institute of Thermomechanics AS CR, v.v.i.	CTU in Prague Faculty of Mech. Engineering Dept. Tech. Mathematics	MIO Université du Sud Toulon Var - AMU - CNRS - IRD	Czech Pilot centre ERCOFTAC

The Influence of Different Geometries of Human Vocal Tract Model on Resonant Frequencies
J. Valášek, P. Sváček, J. Horáček
Abstract:
This paper presents the transfer function approach in order to determine the acoustic resonant frequencies of a human vocal tract model. The transfer function is introduced here as an acoustic pressure ratio between input amplitude at glottis position and output amplitude at mouth opening given by the solution of Helmholtz equation. This equation is numerically approximated by finite element method. The influence of different boundary conditions are studied and also different locations of excitation and microphone. Four different vocal tract geometries motivated by vocal tract geometry for vowel [u:] are investigated. Its acoustic resonance frequencies in range 100 - 2500 Hz are computed and compared with published results. Further, the transient acoustic computation with different acoustic analogies are performed. The frequency spectra of Lighthill analogy, acoustic wave equation and perturbed convective wave equation are compared, where the vocal tract model with best frequency agreement with published results was chosen. The dominant frequencies correspond with predicted frequencies of transfer function approach.
Keywords:
wave equation, transfer function, aeroacoustic analogies, perfectly matched layer

Fulltext: PDF DOI: https://doi.org/10.14311/TPFM.2018.041

In Proceedings Topical Problems of Fluid Mechanics 2018, Prague, 2018 Edited by David Šimurda and Tomáš Bodnár, pp. 307-314 ISBN 978-80-87012-65-9 (Print) ISSN 2336-5781 (Print)