Objective: To investigate the clinical effectiveness and safety of a novel behavioral voice therapy program combining structured vocal exercise with adjunctive neuromuscular electrical stimulation for rehabilitating dysphonia secondary to vocal fold bowing.
Design: Prospective interventional clinical case series with a 3-month follow-up.
Setting: Outpatient speech and hearing clinic in an academic medical center.
Patients: Convenience sample of 7 patients diagnosed by an otolaryngologist as having chronic dysphonia for at least 3 months due to bilateral vocal fold bowing.
Intervention: A novel voice therapy program incorporating exercise principles and sustained phonations of increasing length, volume, and pitch paired with concurrent transcutaneous neuromuscular electrical stimulation.
Main outcome measures: Change in maximum phonation time, highest attainable pitch, glottal closure, supraglottic compression, and Voice Handicap Index.
Results: Maximum phonation time for /i/ increased significantly (z = -2.201, P < .03), with a modest effect demonstrated (Hedges g, 0.65; 95% confidence interval, -0.56 to 1.75). Voice Handicap Index trended toward significance (z = -1.787, P < .07). Glottal closure during phonation improved, and supraglottic compression decreased. Improvements were maintained or enhanced at the 3-month follow-up. Analysis of highest attainable pitch data was limited owing to aperiodicity in the baseline evaluations.
Conclusions: Behavioral voice therapy with adjunctive neuromuscular electrical stimulation reduced vocal fold bowing, resulting in improved acoustic, laryngeal, and patient-centered outcomes. Maximum phonation time and glottal closure results imply increased vocal fold tension secondary to enhanced thyroarytenoid or cricothyroid muscle function after voice therapy.