Experimental validation and physical modelling of vocal folds pathologies

TL;DR

This study combines experimental and physical modelling to understand how vocal fold pathologies affect oscillation patterns and sound production, aiding in diagnosis and treatment.

Contribution

It introduces a validated theoretical vocal fold model that simulates pathologies through geometric and material modifications, bridging experimental and theoretical approaches.

Findings

Close match between measurements and model predictions

Pathology effects simulated by geometry and elasticity modifications

Model provides insights into abnormal vocal fold oscillations

Abstract

Voiced sounds involve self-sustained vocal folds oscillations due to the interaction between the airflow and the vocal folds. Common vocal folds pathologies like polyps and anatomical asymmetry degrade the mechanical vocal fold properties and consequently disturb the normal oscillation pattern resulting in an abnormal sound production. Treatment of voice abnormalities would benefit from an improved understanding between the pathology and the resulting oscillation pattern which motivates physical vocal folds modelling. The current study applies a theoretical vocal folds model to vocal folds pathologies. The theoretical vocal folds model is validated using an experimental set-up simulating the human phonatory apparatus. It consists in a pressure reservoir, a self-oscillating latex replica of the vocal folds and an acoustical resonator. The effects of pathologies are simulated by modifying the replica's geometry, elasticity, and homogeneity under controlled experimental conditions. In general, we observed a close match between measurements and theoretical predictions, which is all the more surprising considering the crudeness of the theoretical model