Computational Modeling of Fluid-Structure-Acoustics Interaction during Voice Production.

Weili Jiang,Qian Xue,Xudong Zheng

doi:10.3389/fbioe.2017.00007

Weili Jiang, Qian Xue + Show 1 more

Open Access

https://doi.org/10.3389/fbioe.2017.00007

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Abstract

The paper presented a three-dimensional, first-principle based fluid–structure–acoustics interaction computer model of voice production, which employed a more realistic human laryngeal and vocal tract geometries. Self-sustained vibrations, important convergent–divergent vibration pattern of the vocal folds, and entrainment of the two dominant vibratory modes were captured. Voice quality-associated parameters including the frequency, open quotient, skewness quotient, and flow rate of the glottal flow waveform were found to be well within the normal physiological ranges. The analogy between the vocal tract and a quarter-wave resonator was demonstrated. The acoustic perturbed flux and pressure inside the glottis were found to be at the same order with their incompressible counterparts, suggesting strong source–filter interactions during voice production. Such high fidelity computational model will be useful for investigating a variety of pathological conditions that involve complex vibrations, such as vocal fold paralysis, vocal nodules, and vocal polyps. The model is also an important step toward a patient-specific surgical planning tool that can serve as a no-risk trial and error platform for different procedures, such as injection of biomaterials and thyroplastic medialization.

Highlights

Voice production is a complex three-way interaction process between the glottal flow dynamics, vocal fold vibrations, and vocal tract acoustics
The jet passes through the supraglottal vocal tract, which primarily serves as an acoustic resonator to reshape the spectrum of the sound source
The adopted hydrodynamic/ acoustic splitting method allowed decomposing the total flow rate into the incompressible component and acoustic perturbation component, which are termed as the incompressible flow rate and acoustic flow rate, respectively, in the subsequent sections

Summary

Introduction

Voice production is a complex three-way interaction process between the glottal flow dynamics, vocal fold vibrations, and vocal tract acoustics. The forced air from the lungs interacts with the adducted vocal folds to initiate self-sustained vibrations. This creates a pulsatile jet in the larynx, which is the sound source. Computer models of voice production have undergone significant improvement from early lumped-mass vocal fold models (Flanagan and Landgraf, 1968; Ishizaka and Flanagan, 1972; Story and Titze, 1995; Zañartu et al, 2007) to recent continuum mechanics-based models (Alipour et al, 2000; Suh and Frankel, 2007; Zhang et al, 2007; Luo et al, 2008; Zheng et al, 2009; Šidlof and Zörner, 2013; Šidlof et al, 2015). Many models assumed a straight rectangle tubular or cylindrical shape for the vocal tract

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