The Outcomes of the Voice Use Reduction Program on Voice Quality and Vocal Fatigue in Occupational Voice Users

The study aimed to describe the outcomes of the voice use reduction (VUR) program on voice quality and vocal fatigue (VF) in occupational voice users (OVUs). A within-subject, quasi-experimental, pre-test, post-test research design was performed on 30 OVUs. Perceptual and acoustic outcome measures were employed pre-and post-implementation of the VUR, including the GRBASI 4-point rating scale, jitter, shimmer, fundamental frequency (F0), harmonic-to-noise ratio (HNR), maximum phonation time (MPT), frequency min and max, intensity min and max, the dysphonia severity index (DSI), and the vocal fatigue index (VFI). The pre-and post-test outcomes revealed significant (p < .001) decreases in perceptual G (Grade of hoarseness), R (Roughness), A (Asthenia), S (Strain), and I (Instability). Perceptual normality in these areas increased significantly (p < .001). Acoustic measures revealed significant (p < .05) decreases in Jitter%, Intensity (dB) Min, and DSI scores as well as significant (p < .05) increases in MPT /a/, /s/, and /z/, Frequency (Hz) Max, and F-0 (Hz) Max, indicating improved voice quality at post-test. The VUR program positively affected and improved OVUs' perception of VF in the areas of tiredness of voice and physical discomfort. OVUs strongly perceive improvement of VF symptoms with rest regardless of the current level of VF they are experiencing. When approaching OVUs, clinicians are encouraged to use a combination of direct voice therapy and vocal hygiene accompanied by VUR to help develop healthier use of the voice, facilitate healing, and prevent further/future injury or disorder.