| Vocal fold vibration is critical to daily communication. Because the structure and function of the vocal folds are unique to the loads they experience, they require in-depth study to understand normal tissue properties and vibratory mechanics, as well as how these properties might change in benign lesion formation. The aim of this thesis is to address questions of vocal fold biomechanics from two angles by studying mucosal wave mechanics and tissue structure. Mucosal wave propagation through vocal fold tissue is essential for healthy vocal fold vibration, and many pathologies impact mucosal wave propagation and cause a hoarse and effortful voice. Despite the importance of mucosal wave function, there exists a gap in knowledge as to how tissue mechanics impact the mucosal wave. Three experiments were performed to address this question.;The first study modeled the effects of elongation on mucosal wave parameters in excised leporine, canine, and porcine models. Results indicated that there was no relationship between either frequency or elongation and vertical phase difference. There was however, a decreasing trend in the time delay between vocal fold lips in the canine model. The second study investigated collagen gradients in leporine, canine, and porcine larynges. There was evidence of a collagen gradient in the porcine model, but the gradient was absent in the canine and rabbit models. Finally, the third study investigated the effects of elongation on collagen orientation. There was evidence of collagen recruitment with increases in collagen alignment and straightness that corresponded with elongation.;Taken together, these studies represent a step toward better understanding the impact of elongation and strain stiffening on the mucosal wave. They also provide evidence to inform animal model selection in studies of vibratory mechanics and tissue structure. Future work can expand on these results to better understand the relationship between tissue structure and mechanical properties. Understanding the tissue structure of the vocal folds, how that impacts material properties, and in turn vibration mechanics, is essential in understanding pathology and developing better treatments for voice disorders. |
