Comparing the Effects of Self-Generated and Platform-Generated Whole Body Vibration on Vocal Fatigue

Summary Objectives A whole body vibration platform using vertical oscillation has been shown to be efficacious in reducing vocal fatigue in adults. This study aimed to investigate whether this platform-generated whole body vibration was unique in reducing vocal fatigue by comparing it with self-generated whole body vibration. Methods Twenty-four female adults (mean age = 23.96 years) were randomly assigned to one of the following three groups: a machine-generated whole body vibration group (N = 8), a self-generated whole body vibration group (N = 8), and a placebo vocal resting group (N = 8). All participants performed a karaoke singing task for at least 95 minutes. Each participant received 10 minutes of platform-generated vibration, self-vibration, or sham localised vibration (placebo group with basically voice rest only), according to their group allocation. Vocal function ability, measured by the highest fundamental frequency produced, and a self-reported vocal fatigue score were evaluated at three time points: baseline (prefatigue), after the singing task (post-fatigue) and post-vibration. Results The study revealed that machine-generated whole body vibration was significantly better at improving vocal fatigue than self-generated whole body vibration or voice rest. Conclusion The findings support previous research that machine-generated whole body vibration is effective in reducing vocal fatigue. The non-significant results of self-generated whole body vibration in terms of relieving vocal fatigue suggest that inadequate vibration frequency or amplitude together with leg muscle fatigue may have been the main factor of ineffectiveness.