The impact of vocal hyperfunction on relative fundamental frequency during voicing offset and onset.

PURPOSE This study tested the hypothesis that individuals with vocal hyperfunction would show decreases in relative fundamental frequency (RFF) surrounding a voiceless consonant. METHOD This retrospective study of 2 clinical databases used speech samples from 15 control participants and women with hyperfunction-related voice disorders: 82 prior to treatment (muscle tension dysphonia, n=22; vocal fold nodules, n=30; vocal fold polyps, N=30) and 18 before and after surgical removal of vocal fold nodules or polyps. Acoustic samples were analyzed with respect to the RFF at the offset and onset of voicing surrounding a voiceless consonant. RESULTS Individuals with vocal hyperfunction in a large clinical sample showed significant lowering of offset and onset RFF compared with controls. Voicing offset and onset RFFs were not significantly changed by the removal of vocal fold lesions in the surgical group. CONCLUSIONS Altered offset and onset RFF in patients with hyperfunction-related voice disorders can be interpreted as a by-product of heightened levels of laryngeal muscle tension. Measurement of RFF during voice offset and onset has potential for use as a simple, noninvasive measure of vocal hyperfunction.