A hybrid approach to the computational aeroacoustics of human voice production

Abstract

The aeroacoustic mechanisms in human voice production are complex coupled processes that are still not fully understood. In this article, a hybrid numerical approach to analyzing sound generation in human voice production is presented. First, the fluid flow problem is solved using a parallel finite-volume computational fluid dynamics (CFD) solver on a fine computational mesh covering the larynx. The CFD simulations are run for four geometrical configurations: both with and without false vocal folds, and with fixed convergent or convergent-divergent motion of the medial vocal fold surface. Then the aeroacoustic sources and propagation of sound waves are calculated using Lighthill's analogy or acoustic perturbation equations on a coarse mesh covering the larynx, vocal tract, and radiation region near the mouth. Aeroacoustic sound sources are investigated in the time and frequency domains to determine their precise origin and correlation with the flow field. The problem of acoustic wave propagation from the larynx and vocal tract into the free field is solved using the finite-element method. Two different vocal-tract shapes are considered and modeled according to MRI vocal-tract data of the vowels /i/ and /u/. The spectra of the radiated sound evaluated from acoustic simulations show good agreement with formant frequencies known from human subjects.

Large-Eddy Simulation of Internal Flow through Human Vocal Folds

“…The velocity is also slightly lower with 2D Smagorinsky and 2D One-Equation compared with [9]. Detailed studies deal with vocal folds are also [11] and [8]. On the Fig.…”

A Unified Numerical Simulation of Vowel Production That Comprises Phonation and the Emitted Sound

“…Recently, unified simulations of phonation and VT acoustics have also been attempted [12,13,14]. However, due to the high computational cost a two step hybrid approach is pursued in those works: the VF movement being obtained from a first FSI simulation, and then prescribed in the computation of the acoustic field.…”

An experimental study of the glottal jet

“…In a computational study, Sidlof et al [14] have shown that the main aeroacoustic sources are located inside glottis, and in places where the glottal jet interacts with the channel wall. The current study aims at highresolution PIV measurements of the velocity fields in domains, which are crucial for source sound generation.…”