Vocal Fold Kinematics in Phonotrauma From High Speed Videoendoscopy.

Abstract

Phonotrauma is believed to result, in part, from elevated vocal fold contact stress associated with increased vocal fold closing speed and vocal hyperfunction. This study aimed to quantify vocal fold vibratory kinematics in phonotrauma, with the hypothesis that closing phase dynamics will be increased in individuals with phonotrauma. Twenty-six women with phonotraumatic vocal fold lesions and 29 vocally healthy control participants underwent high-speed videoendoscopy via a transoral rigid scope while phonating on a sustained /i/. Closing quotient (CQ), speed index (SI), amplitude-to-length ratio (ALR), stiffness index (STI), and maximum area declination rate (MADR) were compared between groups using independent t-tests and Cohen's d effect sizes. Participants with phonotrauma had higher values of ALR (mean [SD], 11.5 [4.3] vs. 8.5 [2.3], p = 0.002, d = 0.86), indicating greater amplitude of vibration compared to controls. Similarly, the MADR was also higher in the phonotrauma group (mean [SD], 1.47 [1.05] vs. 0.51 [0.16] Mpx/s, p < 0.001, d = 1.3), indicating that the vocal fold closing speed was higher in the phonotrauma group. There was no difference in CQ, SI, or STI. These data support the link between phonotraumatic lesions and increased vocal fold contact stress. The findings highlight the maladaptive hyperfunctional cycle that accompanies phonotraumatic lesions and the disruption to vocal efficiency in the setting of phonotrauma.