The Effects of a Vocal Loading Task on the Acoustic and Electromyographic Measurements of Vocal Fatigue

Abstract

The purpose of this study was to determine the effect of a vocal loading task on submandibular muscular activity and acoustic measures of vocal function. Surface electromyography (sEMG) directly assessed muscle activation related to extrinsic laryngeal muscles, and these findings were compared to the acoustic measurements of cepstral peak prominence, low to high spectral ratio, semitone range, and amplitude reflecting the function of intrinsic laryngeal muscles. These measurements were taken from 14 healthy, young adults of the Texas Christian University student population before and after reading Harry Potter and the Sorcerer's Stone for 30 minutes at a volume of at least 75 dB from. Results indicated consistent trends in which acoustic measurement showed more periodic vocal fold movement and reduced vocal range, and sEMG measurement showed reduced muscle activation. An elevated acoustic amplitude suggested that increasing vocal intensity could be a compensatory strategy for individuals with vocal fatigue, but further study is required to test this theory in a larger sample size.