Effects of the Water Resistance Therapy Program on Behavioral Dysphonia: A Physiological Therapeutic Proposal Based on the Principles of Sensorimotor Learning.

Introduction: The main goal of voice therapy is to reestablish the balance of the vocal system through myoelastic and aerodynamic forces. Therefore, the therapeutic method must focus on vocal physiology as a way of reversing the pathology and also be easy for the patient to internalize it. Water resistance therapy (WRT) can meet this demand. In addition, the use of sensorimotor learning (SML) principles can benefit the rehabilitation process. Then, the objectives of this study are to propose a therapeutic program based on the physiological approach and the principles of SML and to verify its effects on individuals diagnosed with behavioral dysphonia.

Methods: Experimental, prospective, and analytical study. Participants in this study were 11 volunteers, aged between 18 and 50 years, with vocal complaints and changes, which constituted a diagnosis of behavioral dysphonia. The volunteers underwent intervention with the WRT Program (with a silicone tube submerged in water), consisting of eight sessions lasting 30 minutes. The following SML principles were adopted: prepractice, practice amount, practice distribution, practice variability, practice schedule, attentional focus, and target complexity. To analyze the effect of the WRT Program, vocal economy and its components, cepstral peak prominence-smoothed (CPPs), alpha ratio, L1-L0, and the vocal and laryngopharyngeal symptoms intensity, the Vocal Fatigue Index (VFI) and the Voice Symptom Scale (VoiSS) were measured before and after the interventions. Data were analyzed using the paired t test and Wilcoxon Test (P < 0.05).

Results: The WRT Program showed an increase in the vocal economy (P = 0.004) and a reduction in the glottal contact quotient (P > 0.001). About acoustic measurements, they did not show statistically significant changes. However, concerning the vocal and laryngopharyngeal symptoms intensity, there was a decrease in "breaking voice" (P = 0.019), "hoarseness" (P = 0.003), "pain when speaking" (P = 0.021), and "strained speaking" (P = 0.005). Furthermore, there was a reduction in VoiSS (P = 0.001) as well as VFI in its total value (P = 0.001) and its subscale "physical discomfort associated with the voice" (P = 0.06).

Conclusion: The WRT Program, as proposed, has positive effects on voice economy and vocal comfort.