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

Abstract

A unified approach for the numerical simulation of vowels is presented, which accounts for the self-oscillations of the vocal folds including contact, the generation of acoustic waves and their propagation through the vocal tract, and the sound emission outwards the mouth. A monolithic incompressible fluid-structure interaction model is used to simulate the interaction between the glottal jet and the vocal folds, whereas the contact model is addressed by means of a level set application of the Eikonal equation. The coupling with acoustics is done through an acoustic analogy stemming from a simplification of the acoustic perturbation equations. This coupling is one-way in the sense that there is no feedback from the acoustics to the flow and mechanical fields.All the involved equations are solved together at each time step and in a single computational run, using the finite element method (FEM). As an application, the production of vowel [i] has been addressed. Despite the complexity of all physical phenomena to be simulated simultaneously, which requires resorting to massively parallel computing, the formant locations of vowel [i] have been well recovered.

Computational aeroacoustics to identify sound sources in the generation of sibilant /s/

“…To end this introductory section, we would like to remark that aside from static vowel sounds, for which an extensive literature is available (see, eg, literature [38][39][40][41][42][43][44][45][46][47][48][49] ), few papers can be found addressing the numerical simulation of other speech sounds. The reason for that is probably the complex physics beneath their generation and the associated high computational cost.…”

An interface‐tracking unified continuum model for fluid‐structure interaction with topology change and full‐friction contact with application to aortic valves

“…The method builds on the unified continuum FSI (UC-FSI) methodology, 48,49 where the fluid and structure subdomains are discretized by a finite element method as one single unified continuum. Preliminary work has shown promise in the area of biomechanics, 50,51 and in this article a detailed description is given of the methodology with a specific focus on heart valve simulation.…”

“…The development of the UC-FSI contact model is inspired by previous work in the field, [36][37][38] but the context of 3D turbulent flow fluid-structure interaction is novel with several promising results in the biomechanics area. 50,51,63…”

Interaction Mechanisms between Glottal Source and Vocal Tract in Pitch Glides

“…However, unified approaches (e.g. Degirmenci et al, 2017) are currently computationally unfeasible for most purposes. The separate glottal source and acoustic load models are connected in Section 4.3 which reviews how these two models interact.…”