Ventricular fold dysphonia: Application of biofeedback technology to a rare voice disorder

A rare case of adult ventricular fold dysphonia was treated using electromyographic (EMG) biofeedback. Ventricular fold dysphonia is a voice disorder in which the ventricular, or false vocal folds, are used to produce speech instead of the true vocal cords. Baseline and treatment EMG recordings were taken during nonvocalizing, counting, and conversational speech. Laryngeal aerodynamic and perceptual measures were also used to detect treatment effects. The treatment program was evaluated using a multiple baseline design with changing criterion. Results indicated that EMG biofeedback was effective in reducing EMG levels during each of the nonvocalizing and speaking phases. Improvements were observed in laryngeal aerodynamic functioning, and voice quality was found to be markedly improved when independently evaluated by voice experts unaware of treatment conditions. Results were maintained at 6-month follow-up, and an endoscopic examination indicated no recurring ventricular phonation.