The effect of superficial hydration, with or without systemic hydration, on vocal quality in female professional singers

Abstract

Objective: Professional voice users exhibit the highest prevalence of voice disorders due to high vocal demands. Education and implementation of counter measures such as preventative vocal hygiene, is therefore vitally important. The aim of this study was to describe the effect of superficial hydration, with or without systemic hydration, on the vocal quality of female professional singers.

Methods: A within-subject, experimental, pre-test post-test research design was implemented. The study replicated the protocol, as executed by Van Wyk et al. (2016). This study however added the experimental conditions of superficial hydration and combined superficial and systemic hydration and their effects on voice quality in female professional singers, between the ages of 18 – 32 years. Participants also completed the Vocal Fatigue Index (VFI). Pre- and post-test perceptual and acoustic voice assessments were conducted on two occasions (1) a control test with no applied hydration and (2) an experimental test where participants were randomly divided into a superficial hydration group or a combined systemic and superficial hydration group. Therefore, each participant acted as their own control.

Results: When comparing pre- and post-test results, a statistically significant increase in maximum phonation time (MPT) values were obtained for the hypo hydrated (p=0.015) and superficial hydration (p=0.004) condition. Furthermore, a significant increase in frequency (Hz) min (p=0.019) within the hypo hydrated condition was also observed. With the combined hydration condition, a significant increase was observed in the intensity (dB) min (p=0.010) and 𝐹����0(Hz) min (p=0.002) scores. Between-group, post-test comparison outcomes revealed that where superficial hydration was applied mean shimmer % (p=0.016), MPT (sec) (p=0.003), and dysphonia severity index (DSI) (p=0.020) scores increased significantly and a significant reduction in mean intensity (dB) max (p=0.049) and intensity (dB) min (p=0.018) was observed.

Conclusion: This study indicated that the use of superficial hydration had positive outcomes on the perceptual parameters of voice quality and symptoms of vocal fatigue in female professional singers. Hydration can therefore be seen as an effective preventative measure in vocal hygiene programs.

Key Words: Female Professional Singers; Phonotrauma; Superficial Hydration; Vocal Fatigue; Systemic Hydration; Vocal Hygiene.