Nonlinear dynamic mechanism of vocal tremor from voice analysis and model simulations

Abstract

Nonlinear dynamic analysis and model simulations are used to study the nonlinear dynamic characteristics of vocal folds with vocal tremor, which can typically be characterized by low frequency modulation and aperiodicity. Tremor voices from patients with disorders such as paresis, Parkinson's disease, hyperfunction, and adductor spasmodic dysphonia show lowdimensional characteristics, differing from random noise. Correlation dimension analysis statistically distinguishes tremor voices from normal voices. Furthermore, a nonlinear tremor model is proposed to study the vibrations of the vocal folds with vocal tremor. Fractal dimensions and positive Lyapunov exponents demonstrate the evidence of chaos in the tremor model, where amplitude and frequency play important roles in governing vocal fold dynamics. Nonlinear dynamic voice analysis and vocal fold modeling may provide a useful set of tools for understanding the dynamic mechanism of vocal tremor in patients with laryngeal diseases.

Simulation of ultrasound beam formation of baiji (Lipotes vexillifer) with a finite element model

“…[9][10][11][12][13][14][15][16][17] In this paper, numerical simulations based on a previous finite element a) Also at Hawaii Institute of Marine Biology, University of Hawaii, 46-007 Lilipuna Road, Kaneohe, HI 96744. b) Author to whom correspondence should be addressed. Electronic mail: yuzhang@xmu.edu.cn modeling study 18 will be employed to describe the biosonar emission processes of the Yangtze River dolphin (Fig.…”

Simulation based estimation of dynamic mechanical properties for viscoelastic materials used for vocal fold models

“…Clinically, the state of the art analysis method of vocal fold vibrations is high-speed video endoscopy [1,2]. Apart from the geometrical dimensions of the vocal folds, their mechanical properties affect the vibration modes [3][4][5][6][7][8]. Hence, there is a great demand for the characterization of the vocal folds in the frequency range of human speech [9,10].…”

Invariant Measures Based on the U‐Correlation Integral: An Application to the Study of Human Voice

“…However, they did not analyze type 4 voices. Another study by Zhang and Jiang conducted over the Kay Elemetrics database reported a mean correlation dimension of = 1.51 for normal voices and = 3.17 for a group with vocal tremor [25]. As far as we know, all researches conducted on normal and pathological voices have used the Grassberger and Procaccia correlation integral to estimate and 2 .…”