Title: Polyps and paralysis phonation classification with nonlinear dynamics model 

Author: GU Lingling; ZHANG Xiaojun; HUANG Chengwei; WU Di; ZHOU Xiaojin; TAO Zhi 

Affiliation: College of Physics,  Optoelectronics and Energy,  Soochow University 

Abstract: In order to provide the basis for parameter selection of vocal diseases classification, a nonlinear dynamic modeling method is proposed. A biomechanical model of vocal cords with polyp or paralysis, which couples to glottal airflow to produce laryngeal sound source, is introduced. And then the fundamental frequency and its perturbation parameters are solved. Poincare section and bifurcation diagram are applied to nonlinear analysis of model vibration. By changing the pathological parameters or subglottal pressure, the changes of fundamental frequency and Lyapunov exponents are analyzed. The simulation results show that, vocal cord paralysis reduces the fundamental frequency, and the chaos occurs only within a certain pressure range; while vocal cord with a polyp don't reduce the fundamental frequency, chaos distributes throughout the entire range of pressure. Therefore this study is helpful for classification of polyp and paralysis by the acoustic diagnoses.