Voice problems are a common occupational hazard of teaching school, yet few studies exist that have objectively evaluated treatment approaches aimed at rehabilitating these occupation-related voice disorders. This randomized clinical trial used patient-based treatment outcome measures to evaluate the effectiveness of three treatment programs. Sixty-four teachers with voice disorders were randomly assigned to 1 of 3 treatment groups: voice amplification using the ChatterVox portable amplifier (VA; n = 25), resonance therapy (RT; n = 19), and respiratory muscle training (RMT; n = 20). Before and after a 6-week treatment phase, all teachers completed (a) the Voice Handicap Index (VHI; B. H. Jacobson et al., 1997), an instrument designed to appraise the self-perceived psychosocial consequences of voice disorders, and (b) a voice severity self-rating scale. Both intention-to-treat and as-treated analyses revealed that only the VA and RT groups reported significant reductions in mean VHI scores and in voice severity self-ratings following treatment. Furthermore, results from a posttreatment questionnaire regarding the perceived benefits of treatment showed that compared to RT and RMT, teachers in the VA group reported significantly more overall voice improvement, greater vocal clarity, and greater ease of speaking and singing voice following treatment. These findings replicate previous results from an earlier clinical trial confirming the efficacy of VA and provide new evidence to support RT as an effective treatment alternative for voice problems in teachers. The results are discussed in the context of uneven levels of self-reported compliance and disparate dropout rates among the treatment groups.