Perceptual and Acoustic Outcomes of Voice Therapy for Male-to-Female Transgender Individuals Immediately After Therapy and 15 Months Later

Objectives. The present study examined how effectively listeners' perceptions of gender could be changed from male to female for male-to-female (MTF) transgender (TG) clients based on the voice signal alone, immediately after voice therapy and at long-term follow-up. Short- and long-term changes in masculinity and femininity ratings and acoustic measures of speaking fundamental frequency (SFF) and vowel formant frequencies were also investigated. Design. Prospective treatment study. Method. Five MTF TG clients, five control female speakers, and five control male speakers provided a variety of speech samples for later analysis. The TG clients then underwent 8 weeks of voice therapy. Voice samples were collected immediately at the termination of therapy and again 15 months later. Two groups of listeners were recruited to evaluate gender and provide masculinity and femininity ratings. Results. Perceptual results revealed that TG subjects were perceived as female 1.9% of the time in the pretest, 50.8% of the time in the immediate posttest, and 33.1% of the time in the long-term posttest. The TG speakers were also perceived as significantly less masculine and more feminine in the immediate posttest and the long-term posttest compared with the pre-test. Some acoustic measures showed significant differences between the pretest and the immediate posttest and long-term posttest. Conclusions. It appeared that 8 weeks of voice therapy could result in vocal changes in MTF TG individuals that persist at least partially for up to 15 months. However, some TG subjects were more successful with voice feminization than others.