Evaluation of voice therapy for dysphonia in adults: follow-up of group effects and individual variability

This study analyzed group and individual differences in the results of vocal rehabilitation in a group of dysphonic patients with different diagnoses, using a brief multidimensional assessment protocol. The voices of 21 participants with dysphonia and 21 controls were evaluated and compared in a pre- vs. post-speech therapy treatment. Voice performance was assessed before and after treatment by a set of tests that included videolaryngostroboscopy, aerodynamic tasks, and self-rating questionnaires. The speech-therapy treatment group received two sessions of speech therapy a week for 3 months. Three follow-up reevaluations of group effects and individual variability were also carried out to assess the latency period after the end of treatment. MANOVA with Pillai's trace test showed a significant group effect of the vocal treatment on all of the variables assessed. A pre- vs. post- treatment T-test of individual changes was also significant in most of the dysphonic participants, despite the wide range of scores (high variance) in the different measures used after the voice therapy program. The results of both group and individual analyses support the effectiveness of vocal rehabilitation with speech therapy in at least some types of voice disorders. However, voice therapy was more effective in participants with certain characteristics and antecedents (AU)