Preliminary investigation of a novel technique for the quantification of the ex vivo biomechanical properties of the vocal folds

The human vocal fold is a complex structure made up of distinct layers that vary in cellular and extracellular matrix composition. Elucidating the mechanical properties of vocal fold tissues is critical for the study of both acoustics and biomechanics of voice production, and essential in the context of vocal fold injury and repair. Both quasistatic and dynamic behavior in the 10-300 Hz range was explored in this preliminary investigation. The resultant properties of the lamina propria were compared to that of the nearby thyroarytenoid muscle. E_r, quantified via quasistatic testing of the lamina propria, was 609 ± 138 MPa and 758 ± 142 MPa in the muscle (p = 0.001). E′ of the lamina propria as determined by dynamic testing was 790 ± 526 MPa compared to 1061 ± 928 MPa in the muscle. Differences in E′ did not achieve statistical significance via linear mixed effect modeling between the tissue types (p = 0.95). In addition, frequency dependence was not significant (p = 0.18).

Highlights Quasistatic testing found E_r of the lamina propria to be lower than the muscle (p = 0.001).E′ was 790 ± 526 MPa for lamina propria and 1061 ± 928 MPa for the muscle.Linear mixed effects of E′ did not find the difference between tissues significant.Dynamic properties of both tissues were not frequency dependent.