Evaluation of the Effectiveness of Electrotherapy in Voice Treatment: A Controlled Randomized Clinical Trial

Transcutaneous electrical nerve stimulation (TENS) is widely used as a therapeutic tool for pain relief, muscle relaxation, and fatigue reduction. Vocal production, in turn, is a complex process involving the interaction of anatomical, physiological, neurological, and emotional factors. In some cases, dysphonia is related to muscular changes, manifesting as excessive contraction of the intrinsic and extrinsic laryngeal muscles and changes in glottal closure. These conditions can lead to continuous vocal effort, favoring the development of nodules, edema, and other impairments, negatively impacting vocal quality, often associated with inappropriate vocal behaviors. The comprehensive voice rehabilitation program (CVRP) was developed to treat behavioral dysphonia in professional voice users, applicable to vocal nodules.

To evaluate the efficacy of CVRP in brief intensive therapy (BIT), combined with low-frequency TENS, in the treatment of women with vocal nodules.

This randomized clinical trial included 40 women (18-55 years) diagnosed with vocal nodules. They were randomly allocated into two groups: a control group (CG), which underwent speech-language-hearing therapy with CVRP in BIT; and an experimental group (EG), which underwent the same protocol associated with transcutaneous electrical nerve stimulation (TENS). Both groups underwent 14 sessions: one for assessment, 12 for therapy, and one for reassessment. TENS was applied for 20 min during EG sessions. Data collection included auditory-perceptual evaluation, acoustic analysis, video laryngoscopy, vocal self-assessment protocols (VoiSS, VHI-10, and VDCQ-10), and pain assessment (algometry and visual analog scale). Statistical analysis considered parametric and nonparametric tests for repeated measures and calculation of the effect size, with a 5% significance level.

CVRP improved vocal quality, increased maximum phonation time (MPT), improved laryngeal imaging, reduced vocal symptoms and self-perceived voice handicap, and increased pressure pain threshold. When combined with TENS, it reduced pain, cervical muscle tension, and the size of laryngeal lesions. These results indicate that CVRP combined with TENS may be effective in treating women with vocal nodules. Further clinical trials using this model, in addition to conventional therapy, are recommended.

CVRP in BIT, with or without electrotherapy, significantly improved the vocal quality of participants, with better results in the group receiving electrotherapy.