Purpose: Motivated by practice and feedback principles of motor learning, an SLP and Mobile app (SAM) protocol for voice feminization was developed to minimize SLP’s role to one of supervision and professional guidance and maximize learning during independent practice outside the session. The purpose of the study was to evaluate the effectiveness and acceptability of the innovative service delivery method. Method: The study used a single-subject changing criterion design. Four trans women completed a 10-week SAM voice intervention program delivered via 30-minute weekly in-clinic sessions and a technology-supported home program. The program was client-centered and incorporated frequent practice with intermittent, knowledge-of-result feedback. Outcome measures included acoustic measures, self and listener ratings of voice femininity and naturalness, and a program evaluation questionnaire. Results: Average F0 of phrases and picture descriptions gradually increased into the feminine range for all participants. Self and listener ratings showed that the trans women were perceived to sound more feminine, yet still natural, following treatment. Participants found the in-clinic sessions useful, the app easy to use, and noted little fatigue or discomfort. Conclusions: The innovative and efficient SAM program for voice feminization was effective relative to the stated aims in terms of acoustic, perceptual and program evaluation measures. There is a need for further studies to elucidate the factors that were key to the success achieved in the current study.
Keywords: male to female transsexual, acoustic voice analysis, perceptual voice analysis, principles of motor learning
