Perceptual Recovery Effects of Thyme Drops after Vocal Loading for Professional Voice Users: A Randomized Placebo-controlled Single-blind Trial

Ab s t r Ac t Objective: The present study aimed to evaluate perceived recovery effects of drops after vocal loading. Particularly, thyme was evaluated, which has promising effects on the mucosa, throat, and airway system. Materials and methods: In total, 48 of 56 vocally healthy professional voice users were included because they presented with vocal fatigue after vocal loading. The subjects were randomized into two groups who received a thyme drop (TD), or a placebo drop (PD), after a 20-minute vocal loading task. The recovery effect by using drops was rated perceptually. Results: The results of the self-perceived rating showed higher significant outcomes for the TD group (p = 0.050 to p = 0.002). The TD group revealed a higher agreement for perceived well-being in the throat (i.e., 83.3%), a higher comfort in talking (i.e., 50.0%), and lower malaise/pain in the throat (58.3%) than the PD group (i.e., agreement of 50.0%, 16.7%, and 20.8%, respectively). Conclusion: Thyme drops might increase the comfort, well-being in the throat, and talking after vocal loading. Further research is necessary to investigate thyme and drops as potential benefit for professional voice users with high vocal loading.