Triangular body-cover model of the vocal folds with coordinated activation of the five intrinsic laryngeal muscles

TL;DR

This paper introduces a novel triangular body-cover model of the vocal folds with full intrinsic muscle control, capturing antagonist muscle co-contraction to better understand voice disorders related to laryngeal muscle coordination.

Contribution

It presents a new self-sustained triangular model that accurately simulates antagonist muscle activation, improving upon previous low-order models for studying vocal fold biomechanics.

Findings

Model agrees with finite element, excised larynx, and clinical data.

Different muscle activation patterns produce distinct vocal fold behaviors.

The model is suitable for studying voice disorders involving muscle coordination.

Abstract

Poor laryngeal muscle coordination that results in abnormal glottal posturing is believed to be a primary etiologic factor in common voice disorders such as non-phonotraumatic vocal hyperfunction. Abnormal activity of antagonistic laryngeal muscles is hypothesized to play a key role in the alteration of normal vocal fold biomechanics that results in the dysphonia associated with such disorders. Current low-order models of the vocal folds are unsatisfactory to test this hypothesis since they do not capture the co-contraction of antagonist laryngeal muscle pairs. To address this limitation, a self-sustained triangular body-cover model with full intrinsic muscle control is introduced. The proposed scheme shows good agreement with prior studies using finite element models, excised larynges, and clinical studies in sustained and time-varying vocal gestures. Simulations of vocal fold posturing obtained with distinct antagonistic muscle activation yield clear differences in kinematic, aerodynamic and acoustic measures. The proposed tool is deemed sufficiently accurate and flexible for future comprehensive investigations of non-phonotraumatic vocal hyperfunction and other laryngeal motor control disorders.