Prevalence, Characteristics and Impact of Dysphonia in US Marine Corps Drill Instructors

Abstract

Prior studies have evaluated various populations at increased risk of voice impairment. However, minimal data is available for military Drill Instructors, a population known to have significant vocal demands. The purpose of this study was to determine the prevalence of subjective, perceptual, and objective dysphonia in this population and to evaluate contributing factors and impact on job performance. Cross-sectional analysis. United States Marine Corps base (Marine Corps Recruit Depot, San Diego, California). Active US Marine Corps Drill Instructors. A survey was administered investigating subjective measures of dysphonia and its impact on occupational function. Standardized voice samples were recorded for objective and perceptual voice analysis. Prevalence of subjective (Voice Handicap Index-10 and Glottal Function Index scores), perceptual (CAPE-V score), and acoustic (Cepstral-spectral index of dysphonia) measures of dysphonia. Subjective dysphonia was present in 47.7% by the Voice Handicap Index-10 and 70.2% by the Glottal Function Index. 51% of subjects reported periods of aphonia, while 47% reported voice problems limiting job function in the month prior to being surveyed. The Cepstral-Spectral Index of Dysphonia Mean was abnormal in 95.3% and CAPE-V overall severity score was abnormal in 94%. There was significant improvement in subjective, perceptual, and acoustic voice outcomes as the amount of time since last training cycle (ie, relative voice rest) and as experience as a Drill Instructor increased, however the VHI-10 was the only measure that normalized. There is a very high prevalence of self-reported dysphonia in Drill Instructors, with near-universal prevalence of some degree of objectively and perceptually-rated dysphonia. Nearly half of those surveyed reported that dysphonia limited their job performance. Relative voice rest and experience seem to mitigate severity, but normal ratings were rare. While objective and perceptually-rated dysphonia are persistent and highly prevalent, it does not necessarily translate into a perceived impairment in this population. For these reasons and considering the importance of extraordinary vocal function in this occupation, Drill Instructors appear to be in dire need of proper voice care to both maximize job performance and mitigate long-term voice-related problems.