Mitigating the Effects of Acute Vocal Exertion in Individuals With Vocal Fatigue

Abstract

Objectives/Hypothesis: To investigate the effects of acute vocal exertion on individuals with vocal fatigue and to determine whether semi-occluded vocal tract exercises (SOVTEs) are more effective than vocal rest in mitigating acute effects.Study Design: Prospective, repeated-measures design.Methods: On consecutive days, 10 individuals (6 males, 4 females) with scores indicating vocal fatigue on the Vocal Fatigue Index completed two 10-minute vocal exertion tasks. Vocal rest or SOVTEs were interspersed in counterbalanced order between exertion tasks. Respiratory kinematic, acoustic, aerodynamic, and self-perceptual measures were collected at baseline, following vocal exertion, following SOVTE/vocal rest, and following the second exertion task.Results: Acute vocal exertion worsened phonation threshold pressure (P < .001) and vocal effort (P < .001) and reduced maximum fundamental frequency (P < .001). Speech was terminated at lower lung volumes following vocal exertion (decreased lung volume termination [LVT], P < .001). Exertion-induced changes in vocal effort and LVT were significantly reversed by both vocal rest and SOVTE. Detrimental changes in voice measures reoccurred following the second vocal exertion task. SOVTE and vocal rest protected against changes in respiratory kinematics when vocal exertion was resumed.Conclusions: Vocal exertion impacted laryngeal, respiratory, and self-perceptual measures in individuals with vocal fatigue. Both SOVTE and vocal rest partially mitigated changes in voice measures and prompted more efficient respiratory strategies that were maintained when vocal exertion resumed. These data increase our understanding of how individuals with vocal fatigue respond to vocal exertion tasks and offer preliminary guidance for optimal clinical recommendations.

The effects of vocal exertion on lung volume measurements and acoustics in speakers reporting high and low vocal fatigue

“…All study procedures were approved by the Purdue University Institutional Review Board (IRB# 1805020623). These data were gathered as part of a larger dissertation study, and the laryngeal and respiratory data collected prior to and following this vocal exertion task have been previously published [ 17 , 34 ]. This current study examined laryngeal and respiratory measures during the vocal exertion task itself.…”

“…Participants carried out two identical vocal exertion tasks on consecutive days. Vocal exertion tasks consisted of ten minutes of repeated loud, sustained vowels at elevated fundamental frequency (F0) [ 17 , 56 ]. Experimental days were scheduled 24 hours apart (+ or– 1 hour) and were identical for the portions of the protocol examined in this study, except that consent and screening procedures were performed on day one.…”

“…Participants followed similar patterns of voice use and food/liquid intake for 24 hours prior to each experimental day. During each experimental day, the vocal exertion task consisted of multiple loud, sustained vowels at elevated fundamental frequency (F0) [ 17 , 56 ]. These vowel productions were repeated until 10 minutes had elapsed.…”

“…Emerging evidence suggests that individuals who experience vocal fatigue respond differently following periods of high vocal demand than their vocally healthy counterparts [ 34 , 44 , 45 ]. This is perhaps not surprising as vocal fatigue is characterized by detrimental self-perceptual or physiological voice changes induced by extended voice use [ 46 – 49 ].…”

“…Differences in vocal demand response in people with high vocal fatigue have been observed primarily in respiratory kinematics, which have been shown to differ in individuals with structural and functional voice disorders [ 3 , 50 , 51 ]. For example, following a loud, prolonged vowel task, individuals reporting high vocal fatigue initiated speech at lower lung volumes [ 34 ]. Following the same task, individuals with low vocal fatigue increased lung volume initiation, presumably to benefit from increased recoil forces and thereby improve respiratory efficiency [ 17 ].…”