Indirect Vocal Therapy as a Treatment Program for Behavioral Dysphonia: A Pilot Study

Abstract

Introduction: Indirect vocal therapy (IVT) has tools that aim to modify an individual’s behavior, emotional factors, and physical environment for restoring vocal quality. Then, vocal health guidance may promote the desire for caring about the voice and prevent or treat behavioral dysphonia. However, studies that used parts of IVT have shown conflicting results. Hence, the main objective of this study was to introduce an IVT program based on the taxonomy of Van Stan et al. [Am J Speech Lang Pathol. 2015;24(2):101–25]. The second objective of this study was to analyze the preliminary effects of the IVT program on vocal comfort through the self-assessment of vocal fatigue, vocal symptoms, vocal handicap, and vocal quality in patients diagnosed with behavioral dysphonia. Method: This is an experimental, analytical, and prospective pilot study. Nine participants (five women; four men) aged between 18 and 50 years with behavioral dysphonia participated in this study. They underwent the IVT program with guidance about vocal health, general health, emotional factors, and motivation. The therapy was implemented twice per week, totalizing eight sessions, each lasting 35 min. Participants were assessed before therapy started (M1), after it ended (M2), and 1 month after as a follow-up (M3). As assessment, participants filled in the Vocal Fatigue Index (VFI), Voice Symptoms Scale (VoiSS), and Vocal Handicap Index-30 (VHI-30). Additionally, they had their voices recorded for acoustic measures (i.e., cepstral peak prominence-smoothed, alpha ratio, and L1-L0) and auditory-perceptual analysis using the GRBASI scale. Results: The acoustic measures and auditory-perceptual analysis showed no significant differences between the assessment moments. The auditory-perceptual analysis showed a mild deviation in participants’ vocal quality. The participants’ scores of the VFI, VoiSS, and VHI were lower in M2 and remained lower in M3. Conclusion: The IVT program had positive results in voice-related self-assessment and vocal comfort. However, further studies are necessary to elucidate its effects on the vocal quality of participants with behavioral dysphonia.