Gender in human phonation: Fluid–structure interaction and vocal fold morphology

Abstract

This paper aims to examine the effects of variations in the vocal fold (VF) morphological features associated with gender on glottal aerodynamics and tissue deformation. Nine three-dimensional geometries of the VFs in the larynx are created with various VF lengths, thicknesses, and depths to perform a parametric analysis according to gender-related geometrical parameters. The computational model is incorporated in a fluid–structure interaction methodology by adopting the transient Navier–Stokes equations to model airflow through the larynx and considering a linear elasticity model for VF dynamics. The model predictions, such as aerodynamic data through the larynx, glottal airflow, and VF deformations, are analyzed. The comparison of the simulation results for the nine cases supports the hypothesis that gender differences in laryngeal dimensions remarkably influence the glottal airflow and deformation of the VFs. Decreasing VF thickness and increasing its length corresponds to a noticeable increase in maximum tissue displacement, while variations in depth affect the flow rate significantly in the small and large larynges. Conversely, we observed that the pressure drop at the glottis is nearly independent of the VF length. A comparison of the glottal area with published imaging data illustrated a direct correlation between the glottal configuration and the morphology of the VFs.

Nonlinear Phenomena of Fluid Flow in a Bioinspired Two-Dimensional Geometric Symmetric Channel with Sudden Expansion and Contraction

“…A clinical study has demonstrated the differences in vocal tract geometry between males and females [4]. McCollum et al [5] numerically simulated the airflow in nine channel models with different geometry and gave the vibrations of vocal tracts under the action of airflow, thus indicating the effect of changes in geometry on vocalization. Šidlof [6] has also explored the vocalization process of the human vocal tract through numerical simulation.…”

“…It is notable that the geometries of the channels considered in the literature [5,6] are symmetric, while the numerical results of the flow fields are asymmetric at some specific value ranges of the characteristic parameter Reynolds number (Re). In addition, all the boundary conditions of the given problem are independent of time; however, the numerical results of the flow field are oscillatory and time dependent when Re exceeds a certain Mathematics 2024, 12, 553 2 of 14 critical value (Rec).…”