ABSTRACT
OBJECTIVES: The aim was to compare voice outcomes over time in patients treated with Imitation Model voice therapy and Verbal Instructions Model voice therapy. METHODS: A prospective clinical trial was performed with 56 consecutive patients diagnosed with a primary or secondary functional voice disorder. Thirty-one patients were included for voice therapy following the Imitation Model and 25 patients for the Verbal Instructions Model. Assessments included a self-rated Voice Handicap Index, self-perceived hoarseness and vocal fatigue, perceptual voice evaluation by a Speech Language Pathologist, and maximum Voice Range Profiles. All assessments were completed before therapy, at end of therapy, at six-months posttherapy follow-up and 12-months posttherapy follow-up. For maximum Voice Range Profiles group differences were also compared for effects from end-of-treatment to follow-up assessments. Linear mixed models were used for analysis. RESULTS: Comparison between treatment groups showed significantly larger long-term improvement from the baseline, for verbal instructions model as compared to imitation model for Voice Handicap Index total, and also the physical and emotional subscales, while there was no difference between groups for the functional subscale. Also, voice quality improved more after verbal instructions model, as compared to imitation model, at end of therapy. Results from self-rated hoarseness and vocal fatigue showed no difference between groups. There was no difference between treatment groups in the change of maximum Voice Range Profile from end-of-treatment to follow-up assessments. CONCLUSIONS: The study showed that both Imitation Model voice therapy and Verbal Instructions Model voice therapy improved voice function. Compared to Imitation Model, the Verbal Instructions model showed larger long-term effect on physical and emotional aspects of voice function in everyday life. The two approaches for voice therapy might have different impacts on patients' learning.
ABSTRACT
OBJECTIVE: A stumbling-block in voice therapy is how the patient will be able to apply the new voice technique in everyday life. Possibly this generalization process could be facilitated by giving voice therapy in group because of the natural forum for training voice-to-speech early in communication between the patients in a group setting. The aim of the study was to compare treatment results from individual voice therapy and voice therapy in group, at several time points and in comparison to patients with no voice therapy. METHODS: A randomized treatment study was performed with 77 consecutive patients diagnosed with a functional voice disorder. Thirty-one patients were randomized to individual and group therapy, respectively, and 15 patients to no therapy. The assessments included standardized voice recording and registration of voice range profile (VRP), answering Voice handicap index (VHI) and visual analogue scales for self-hoarseness and self-vocal fatigue, and perceptual voice evaluation by speech-language pathologist. The assessments were performed before, direct after therapy, and three months later in all groups. The 2 therapy groups were also assessed 12 months after therapy. RESULTS: All VHI scores as well as the self-ratings of hoarseness and vocal fatigue, and the perceptual evaluation of voice quality and maximum VRP improved significantly in both therapy groups 3 months after treatment and at 12 months follow-up. There were no significant changes in the control group, with the exception of decreased self-rated hoarseness and increased maximum VRP. Comparisons between treatment groups showed significant larger improvement after group therapy for VHI physical subscale at 12 months, as well as significant lower VHI total score at all measurement sessions and lower subscale scores at 12 months. There were no differences between treatment groups in self-hoarseness or self-vocal fatigue and no difference in perceptual voice quality or VRP. Comparison between controls and treatment groups showed significant larger change in treatment groups from baseline to three months in VHI total and to end of therapy in functional subscale. Treatment groups also showed significant lower scores than controls at each measurement session, for VHI total and physical subscale as well as lower degree of perceptual aberration of voice quality and vocal fatigue, at three months follow-up. CONCLUSIONS: This study shows long-term improvement from behavioral voice therapy, particularly in a group setting. The results indicate the importance of early transfer-to-speech and late posttherapy test to capture whether the goal of voice therapy was fulfilled or not for the patients.
