Effect of vocal therapy associated with electromyographic biofeedback in women with behavioral dysphonia: randomized controlled blinded clinical trial

INTRODUCTION: dysphonia can affect the respiratory, glottic and ressonantal/articulatory levels, this limits the efficiency of communication and can cause quality of life damages. When the etiology of dysphonia is related to incorrect vocal use, it is classified as behavioral. Although the literature shows the effectiveness of several methods and programs of vocal rehabilitation, few investigate the self-perception and the participation of the body musculature in the dysphonia. In order to improve these issues, the literature proposed the electromyographic biofeedback. The studies that analyzed this method are remote and have methodological heterogeneity which makes it difficult to reproduce. Thus, it is necessary to analyze the effect of the method through a clinical trial to obtain scientific evidence on the intervention to support evidence-based clinical practice. PURPOSE: to analyze the effectiveness and duration of the effects of vocal therapy associated with electromyographic biofeedback in women with behavioral dysphonia. STUDY DESIGN: randomized controlled blinded clinical trial. METHODS: Twenty-two women (18 to 45 years) with a diagnosis of behavioral dysphonia were randomly divided into two groups: Experimental Group (EG) - 11 women participated in vocal therapy associated with the application of electromyographic biofeedback of the sternocleidomastoid and supra-hyoids muscles; Placebo Group (GP) - 11 women participated in vocal therapy associated with the application of placebo electromyographic biofeedback. Both groups performed eight therapy sessions, twice a week, lasting 30 minutes. The vocal therapy of both groups was composed of semioccluded vocal tract exercises (trill, humming and fricative sounds). The evaluations were performed at four time points: before, after, one and three months after the vocal therapy and will consist of the assessments: vocal (auditory-perceptual and acoustic evaluation), surface electromyographic, vocal self-assessment, vocal and laryngeal symptoms, musculoskeletal pain and quality of life in voice. The data were analyzed statistically comparing the groups and the time of evaluation (p≤0.05). RESULTS: The proposed vocal therapy promoted positive results in vocal quality, laryngeal and vocal symptoms, voice-related quality of life and muscular electrical activity during rest in women with behavioral dysphonia for both groups. Electromyographic biofeedback promoted additional positive results in muscle electrical activity during phonatory tasks and musculoskeletal pain in women with behavioral dysphonia. These results are based on the behavioral and muscular aspects of the extrinsic region of the larynx, scapular and cervical muscles. CONCLUSION: in this study, the vocal therapy associated with electromyographic biofeedback had equivalent efficacy to traditional therapy in the larynx, voice and self-assessment of symptoms and quality of life. The biofeedback was more effective than traditional therapy on muscular electrical activity and self-perception of musculoskeletal pain and had effects that remained for a longer time in women with behavioral dysphonia.