Objective: Vocal hyperfunction (VH) is a common symptom in many voice disorders and is characterized by excessive laryngeal muscle tension. Its etiology is not well understood, and many factors have been theorized to contribute, including sensorimotor deficits, altered biomechanics, personality traits, and atypical autonomic arousal. Of these, autonomic arousal is the least studied. The purpose of this study was to investigate physiologic measures of autonomic arousal in speakers with and without VH, and their relationships with voice acoustics.

Methods: Speakers with (N = 24) and without (N = 24) VH completed three speaking tasks, intended to modulate autonomic arousal: a reading passage, spontaneous speech, and embedded Stroop sentences. Acoustic and autonomic activity were simultaneously collected. Acoustic measures analyzed were fundamental frequency, cepstral peak prominence, low/high ratio, sound pressure level, and percent pause time. Autonomic measures were analyzed from the electrodermal signal including the amplitude, rise time, half-recovery time, and frequency of the skin conductance response (SCR). A multivariate ANOVA was used to analyze all of the autonomic measures in relation to group, task, and their interaction. A multivariate ANCOVA was used to analyze all of the acoustic measures in relation to group, task, and their interaction while also including autonomic measures as covariates.

Results: We observed a significant effect of task and group, but not their interaction on the autonomic measures. Post hoc analyses revealed a significant effect of 1) group on SCR amplitudes (speakers with VH experiencing more arousal) and 2) group, task, and their interaction on the frequency of SCRs (with increased cognitive load, speakers with VH experience more arousal relative to controls). We are observed a significant effect of task and group, but not their interactions, as well as significant effects of the SCR amplitude, rise time, and frequency of SCRs in the acoustic model. Post hoc analyses revealed: 1) decreased sound pressure level associated with increased arousal, 2) increased cognitive load associated with increased low-high ratio, 3) increased arousal associated with decreased cepstral peak prominence, and 4) increased percent pause time associated with increased arousal and cognitive load.

Conclusions: Autonomic arousal differs in speakers with VH and the extent to which these differences impact speech varies.