Purpose: The aim of the present study was to investigate the efficacy of different straw phonation doses for vocal fatigue (VF) prevention.
Method: Thirteen males and 13 females participated in the study. Each participant received seven preventive treatments (i.e. voice rest with hydration for 15 minutes, straw phonation into air or water for one, three and five minutes) in separate visits. Phonatory threshold pressure (PTP) and self-perceived vocal fatigue (PVF) symptoms severity were adopted as the primary and secondary outcome measures, respectively. Measurements were taken before and after the preventive treatment, and after a 90-minute VF-inducing task.
Result: PTP was maintained in four of the straw phonation doses, namely; the one-minute into air, one-minute, three-minute and five-minute into water conditions; but not in the voice rest condition. Straw phonation into water of a depth of 5 cm for one minute was considered the optimal dose for VF prevention. PVF, however, was not maintained after VF-inducing task in all treatment conditions.
Conclusion: Straw phonation into water for one minute was capable of preventing phonatory efficiency (as measured with PTP) from deteriorating. The dose identified in the present study may be adopted for future prevention studies in population that is vulnerable to VF.
Keywords: prevention; semi-occluded vocal tract; straw phonation; vocal fatigue.