Zeitschrift für Sprachpathologie und Therapie

Abstrakt

The Effect of a Vocal Loading Task on Vocal Function Before and After 24 Hours of Thickened Liquid Use

Mary Gorham-Rowan, Alyson Berndt, Matthew Carter,Richard Morris

Objective: To determine the effect of a vocal loading task on vocal function before and after 24 hours of thickened liquid use.

Methods: Seven healthy adults, ages 19 to 52 years of age, were recruited as participants. Baseline data regarding daily food/liquid intake and urine specific gravity levels (USG) as a marker of hydration were obtained. Participants then completed a vocal loading task, which consisted of 3 × 10 repetitions of a sustained vowel task at 65 dB to 75 dB SPL. Voice recordings and subjective ratings of vocal fatigue and muscle soreness were obtained prior to and following the vocal loading task for both the pre-thickened liquid and post-thickened liquid experimental session. The voice samples were analyzed for changes in fundamental frequency, loudness, and perturbation measures.

Results: There was a significant main effect of vocal loading on vocal loudness as well as subjective ratings of vocal fatigue and muscle soreness; all parameters were higher post-vocal loading. There was also a significant main effect of thickened liquid use on jitter, as jitter levels were substantially lower post-thickened liquids.

Conclusion: The objective and subjective changes reported by the participants’ post-vocal loading are consistent with prior reports concerning normal adaptive responses to greater vocal demands and increased muscular effort. A brief period of thickened liquids does not appear to affect vocal function.