Voice amplification versus vocal hygiene instruction for teachers with voice disorders: a treatment outcomes study

Voice problems are common among schoolteachers. This prospective, randomized clinical trial used patient-based treatment outcomes measures combined with acoustic analysis to evaluate the effectiveness of two treatment programs. Forty-four voice-disordered teachers were randomly assigned to one of three groups: voice amplification using the ChatterVox portable amplifier (VA, n = 15), vocal hygiene (VH, n = 15), and a nontreatment control group (n = 14). Before and after a 6-week treatment phase, all teachers completed: (a) the Voice Handicap Index (VHI), an instrument designed to appraise the self-perceived psychosocial consequences of voice disorders; (b) a voice severity self-rating scale; and (c) an audiorecording for later acoustic analysis. Based on pre- and posttreatment comparisons, only the amplification group experienced significant reductions on mean VHI scores (p = .045), voice severity self-ratings (p = .012), and the acoustic measures of percent jitter (p = .031) and shimmer (p = .008). The nontreatment control group reported a significant increase in level of vocal handicap as assessed by the VHI (p = .012). Although most pre- to posttreatment changes were in the desired direction, no significant improvements were observed within the VH group on any of the dependent measures. Between-group comparisons involving the three possible pairings of the groups revealed a pattern of results to suggest that: (a) compared to the control group, both treatment groups (i.e., VA and VH) experienced significantly more improvement on specific outcomes measures and (b) there were no significant differences between the VA and VH groups to indicate superiority of one treatment over another. Results, however, from a posttreatment questionnaire regarding the perceived benefits of treatment revealed that, compared to the VH group, the VA group reported more clarity of their speaking and singing voice (p = .061), greater ease of voice production (p = .001), and greater compliance with the treatment program (p = .045). These findings clearly support the clinical utility of voice amplification as an alternative for the treatment of voice problems in teachers.