Transgender Voice and Communication: Research Evidence Underpinning Voice Intervention for Male-to-Female Transsexual Women

Transsexual clients seek speech-language pathology services to achieve voice characteristics congruent with their true gender. Male-to-Female Transsexual Women (MtF women) make up the majority of transsexual clients on clinicians' caseloads. For many MtF women, achieving gender congruent voice is critical to psychosocial and financial wellbeing and quality of life. It is incumbent on clinicians who offer voice services to MtF women to use the best evidence available for effective voice training. There is strong evidence that voice feminization should target increasing fundamental frequency to approximately 180 Hz and increasing formant frequencies close to biological female (cisfemale) levels, as well as some evidence that increasing fundamental frequency variability and minimum and maximum fundamental frequency, decreasing vocal effort and intensity, and increasing breathiness are an important focus of intervention. While further research is required, the evidence base is increasing. It is encouraging that studies indicate that most MtF women achieve vocal improvements and that most are satisfied with voice training. Important next steps are to increase the quality of research designs, increase sample sizes, and measure long-term voice outcomes. Expert clinicians in collaboration with MtF women's self-advocacy groups will then be able to develop clinical guidelines for this expanding area of practice.