Acoustic Analysis of Voice Change in Normal Speakers Following Transcutaneous Electrical Stimulation to the Laryngeal Area

ABSTRACT

Transcutaneous electrical stimulation (TES) is being used more frequently by speech-language pathologists to treat individuals with dysphagia since the advent of VitalStim®. Anecdotal reports suggest changes in voice quality associated with TES. This study was completed to examine acoustic measures of voice change in normal speakers following TES. Thirty speakers with normal voices, ages 19-59, received 1 hour of TES administered via two pairs of surface electrodes on the anterior neck. Voice recordings were obtained before and after TES, as well as subjective reports post-TES. The results of the study revealed nonsignificant changes in the acoustic voice measures following TES; these changes were highly variable. Participants reported no sensation, a feeling of vocal warm-up, vocal fatigue and/or delayed onset muscle soreness following TES. Some factors that may contribute to these findings include the amount of subcutaneous fat in the laryngeal area and attempts to resist hyolaryngeal lowering associated with TES.