Uncovering the Impact of Morphological Features on Vocal Fold Function

The human phonation involves complex interactions of airflow through the larynx and the flow-induced vibrations of the vocal folds. The vocal fold of men and women differ in their anatomic and physiological characteristics, which have repercussions on their vibratory patterns. However, no previous research has attempted to explore the implication of differences in the structural dimensions on phonation process. The objective of this study is to perform a parametric analysis to explore the effect of variation in these morphological features on the glottal aerodynamic and the tissue deformation in a systematic manner. Geometric variations studied include vocal fold thickness and length, as well as the vocal folds depth. The fluid-structure interaction simulations of the dynamic vocal folds coupled to the unsteady, turbulent motion of the air past them is performed for nine cases with variable dimensions and vocal fold vibration and the resulting model outcomes such as pulsatile glottal jet, tissue deformation and several metrics for stress distributions are analyzed. We observed that the vocal fold thickness and depth are the parameters that influence the tissue deformations and stresses during phonation, while there was little effect from the vocal fold length.