Overview on state-of-the-art numerical modeling of the phonation process

Abstract

Numerical modeling of the human phonatory process has become more and more in focus during the last two decades. The increase in computational power and the use of high-performance computation (HPC) yielded more complex models being closer to the actual fluid-structure-acoustic interaction (FSAI) within the human phonatory process. However, several different simulation approaches with varying mathematical complexity and focus on certain parts of the phonatory process exist. Currently, models are suggested based on ordinary differential equations (reduced order models) but also on partial differential equations based on continuum mechanics as e.g. the Navier–Stokes equations for the flow discretized by Finite-Volume or Finite-Element-Methods. This review will illuminate current trends and recent progress within the area. In summary, the ultimate simulation model satisfying all physiological needs and scientific opinions still has to be developed.

Flow-induced oscillations of vocal-fold replicas with tuned extensibility and material properties

“…In parallel, over the past decades, a number of theoretical and numerical studies have also addressed the impact of vocal-fold mechanical properties on phonation 30 , 31 , using either vibrating string/beam models of vocal folds to study their natural mode frequencies 32 – 35 , reduced-order phonation models with simplified fluid-structure interactions (e.g., 36 – 40 ) or highly resolved ones commonly based on 3D finite-element methods to simulate tissues biomechanics (e.g., 41 – 44 ). In particular, variations in the tensile, shear and bending stiffness of the vocal folds, as well as in the stresses they undergo during longitudinal elongation (i.e., in the anterior–posterior direction), should contribute strongly to the regulation of their natural vibration frequencies 32 – 35 .…”

On the Alignment of Acoustic and Coupled Mechanic-Acoustic Eigenmodes in Phonation by Supraglottal Duct Variations

“…Using the linear acoustic wave equation [24] (Equation (5.28)) to describe the acoustic field in the context of human phonation is state of the art and this approach is commonly used in the literature, e.g., [1,3,16,25]. Therefore, the acoustic field in a 3D acoustic domain…”

“…The human voice is physically created in a complex process characterized by fluidstructure-acoustic interaction [1]. In this process, the vocal folds are excited to vibrate by the airflow of the lungs V. During vocal fold vibration, the superficial tissue of the vocal fold moves in a wave-like manner, exhibiting a vertical phase difference.…”

An experiment on an automated literature survey of data-driven speech enhancement methods

“…After it transitioned to Open Access (OA) in 2020 [13], Acta Acustica featured three review articles on the state-ofthe-art (SOTA) of the acoustics-related topics: in 2021, McLachlan et al [14] reviewed the use of Bayesian inference in recent developments on sound localization and the relevance of dynamic cues as a way of explaining behavioral human data; in 2022, Rafaely et al [15] provided an updated account of emerging methods in spatial audio signal processing for binaural sound reproduction, including perceptually motivated approaches, beamforming, ML related approaches, among others; and, in 2023, Döllinger et al [16] surveyed current trends and progress in numerical modeling of the human phonatory process, including reduced order models, fluid mechanics approaches and models combined with ML methods.…”