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Phonatory effects of body fluid removal
K V Fisher1, J Ligon, J L Sobecks
1Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL 60208, USA. kim-fisher@northwestern.edu
Journal of Speech, Language, and Hearing Research : JSLHR
|April 28, 2001
Summary
Reducing body fluid, without causing dehydration, significantly increases phonation threshold pressure (Pth) and negatively impacts voice quality. This suggests vocal fold hydration is crucial for clear phonation.
Area of Science:
- Physiology
- Otolaryngology
- Nephrology
Background:
- Vocal fold hydration is essential for normal phonation.
- The precise impact of extracellular fluid volume changes on voice production is not fully understood.
Purpose of the Study:
- To investigate the effect of controlled body fluid reduction on phonation threshold pressure (Pth), vocal effort, and voice quality.
- To determine if extracellular volume depletion, independent of dehydration, affects voice parameters.
Main Methods:
- Employed a single-subject, full-reversal design in adults with end-stage renal disease undergoing ultrafiltration.
- Monitored Pth, vocal effort, voice quality, blood pressure, and heart rate longitudinally.
- Included placebo and healthy controls for comparison.
Main Results:
- Significant increases in Pth were observed with fluid volume reduction (3-4% body weight) in 4 of 6 treated subjects, reversing with fluid replacement.
- Fluid loss explained substantial variance in Pth (31.6%) and perceived vocal effort (40.0%).
- Autonomic nervous system indicators (heart rate, blood pressure) correlated with Pth and fluid volume reduction.
Conclusions:
- Substantial extracellular volume depletion, even without dehydration, can induce voice symptoms.
- Autonomic nervous system modulation may mediate the observed voice changes.
- Vocal fold intrinsic mechanisms likely regulate water flux and respond to hydration status.
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