Publication detail
Finite Element Modelling of the Effect of Stiffness and Damping of Vocal Fold Layers on their Vibrations and Produced Sound
HÁJEK, P. ŠVANCARA, P. HORÁČEK, J. ŠVEC, J. G.
English title
Finite Element Modelling of the Effect of Stiffness and Damping of Vocal Fold Layers on their Vibrations and Produced Sound
Type
journal article - other
Language
en
Original abstract
The study presents a two-dimensional (2D) finite element (FE) model of the fluid-structure-acoustic interaction during self-sustained oscillation of the human vocal folds (VF). The FE model combines the FE models of the VF, trachea and a simplified human vocal tract shaped for phonation of a Czech vowel [a:]. The developed FE model comprises large deformations of the VF tissue, VF contact, fluid-structure interaction (FSI), morphing of the fluid mesh according to the VF motion (Arbitrary Lagrangian-Eulerian approach), solution of unsteady viscous compressible airflow described by the Navier-Stokes equations and airflow separation during the glottis closure. The effect of stiffness and damping of lamina propria, which can be caused by certain VF pathologies, on VF vibrations and produced sound are analyzed. The numerical simulations showed that stiffer lamina propria results in a decrease of the maximum width of glottal opening and in a decrease of the fundamental vibration frequency. Stiffer lamina propria also leads to an increase of maximum of the subglottal pressure and it causes amplitude decrease and flattening of the first and second formant in the spectrum of acoustic pressures. Higher values of lamina propria damping result in the amplitude decrease and flattening of all formants.
English abstract
The study presents a two-dimensional (2D) finite element (FE) model of the fluid-structure-acoustic interaction during self-sustained oscillation of the human vocal folds (VF). The FE model combines the FE models of the VF, trachea and a simplified human vocal tract shaped for phonation of a Czech vowel [a:]. The developed FE model comprises large deformations of the VF tissue, VF contact, fluid-structure interaction (FSI), morphing of the fluid mesh according to the VF motion (Arbitrary Lagrangian-Eulerian approach), solution of unsteady viscous compressible airflow described by the Navier-Stokes equations and airflow separation during the glottis closure. The effect of stiffness and damping of lamina propria, which can be caused by certain VF pathologies, on VF vibrations and produced sound are analyzed. The numerical simulations showed that stiffer lamina propria results in a decrease of the maximum width of glottal opening and in a decrease of the fundamental vibration frequency. Stiffer lamina propria also leads to an increase of maximum of the subglottal pressure and it causes amplitude decrease and flattening of the first and second formant in the spectrum of acoustic pressures. Higher values of lamina propria damping result in the amplitude decrease and flattening of all formants.
Keywords in English
Biomechanics of voice; Simulation of phonation; Fluid-structure-acoustic interaction; Finite element method
Released
01.01.2016
Publisher
Trans Tech Publications Inc.
ISBN
978-3-03835-700-1
ISSN
1662-7482
Book
Engineering Mechanics 2015
Number
821
Pages from–to
657–664
Pages count
8
BIBTEX
@article{BUT119426,
author="Petr {Hájek} and Pavel {Švancara} and Jaromír {Horáček} and Jan G. {Švec},
title="Finite Element Modelling of the Effect of Stiffness and Damping of Vocal Fold Layers on their Vibrations and Produced Sound",
booktitle="Engineering Mechanics 2015",
year="2016",
number="821",
month="January",
pages="657--664",
publisher="Trans Tech Publications Inc.",
isbn="978-3-03835-700-1",
issn="1662-7482"
}