Validation of a novel vocal demand task for measuring vocal fatigue - Project Summary/Abstract
Vocal fatigue is a communication disorder that disproportionately affects occupational voice users such
as teachers, call center workers, and religious officials.1–3 Classically, fatigue is composed of two dimensions:
perceived fatigue and decrements in task performance.4–6 Researchers in exercise science use a variety of task
protocols to elicit perceived fatigue and task performance decrements in the muscle. Only one task protocol,
however—loud oral reading—is prevalent in voice research.7 Loud oral reading tasks take 1-2 hours to
administer7 and expose vocally vulnerable participants to large vocal fold vibratory doses8–10 that may place them
at risk of injury. In the ideal, vocal demand tasks (1) take fewer than 30 minutes to administer, (2) minimize vocal
fold vibratory dose, and (3) maximize the contractile demands placed on the intrinsic laryngeal skeletal muscles
most susceptible to fatigue. The goal of the proposed study is to validate a vocal demand task (the Fluid Interval
Test for Voice, or FIT-V) that cleaves as closely as possible to these ideals, with the goal of sparking future vocal
fatigue research and detecting, diagnosing, and treating vocal fatigue prior to the point of disability. Three specific
aims support this goal: (SA1) to compare changes in perceived vocal exertion between the FIT-V task protocol
and two control task protocols, (SA2) to compare vocal fold distance dose between the three tasks, assessing
whether the FIT-V is non-inferior to the current standard in occupational vibratory risk,10,11 and (SA3) to screen
several potential indices of task performance decrement, including pressure, flow, and biomechanical measures.
The proposed training plan overseen by the University of Delaware uses multiple modalities to enhance
the applicant’s ability to investigate vocal fatigue and become an independent, productive research scientist.
First, mentored in-person and virtual training in disciplines such as perceived exertion, bioenergetics, and
neuromuscular physiology will continue to develop the applicant’s proficiency in fatigue theory and integrated
physiological systems. Second, coursework in clinical exercise physiology instrumentation and paradigms of
performance testing will augment the applicant’s interdisciplinary rigor and ability to import new techniques,
methods, and perspectives to voice science. Third, mentored in-person training and coursework will support the
applicant’s ability to use advanced statistical techniques to analyze time-series data and accurately describe
intrasubject change in fatigability over time. Fourth, data management training will improve the applicant’s ability
to disseminate research findings and protect participant confidentiality. Fifth and finally, mentored training and
distance coursework will teach the applicant to create simulation models of physiological systems and fatigue.
These training aims will give the applicant multiple avenues through which to build upon existing experimental
fatigue paradigms and innovate new approaches to the study of this disabling communication disorder.
