Factors Influencing Auditory Perception of Masculinity and Naturalness in Transmasculine Voices

Purpose: This study examined speaker- and listener-related factors that influence auditory perception of masculinity, naturalness, and gender attribution in transmasculine voices on hormone replacement therapy and in cisgender speakers. Method: Voice recordings were collected from six transmasculine and 12 age-matched cisgender individuals. One hundred five listeners of varying age, sexual orientation, and gender identity rated voices for masculinity and naturalness as well as attributed a gender to each voice. Speaker- and listener-related predictors of voice ratings were examined. Speaker-related factors included speaker gender, acoustic measures of voice quality, and self-report of vocal function. Acoustic measures included fundamental frequency ( F 0), smoothed cepstral peak prominence, F 0 range, Dysphonia Severity Index, and perturbation measures. Self-perceptual measures included speaker ratings of their own voice's masculinity/femininity and naturalness, as well as the Voice Handicap Index (VHI). Listener-related factors included age, gender, and sexual orientation. Results: Ratings of voice naturalness and masculinity were predicted by F 0 on connected speech ( p < .01). Masculinity was negatively associated with F 0 ( r = .79), and naturalness significantly increased when F 0 was within normative range for cisgender speakers ( p < .01). Ratings of naturalness differed across generational groups as older listeners rated transmasculine voices as significantly less natural than cisgender voices ( p < .01). For transmasculine voices, listener age moderated the relationship between masculinity and naturalness, as these parameters were more strongly associated for older listeners ( r = .41) and less so for younger listeners ( r = .18–.23). Transmasculine speakers were 21% more likely to be misgendered than cisgender speakers ( p < .01). Transmasculine voices were acoustically similar to cismale voices; however, VHI scores were significantly higher in transmasculine participants ( p < .01). Conclusions: Although transmasculine and cis male voices were acoustically similar, both speakers and listeners rated transmasculine voices as less masculine and less natural than cis male voices. Listener age influenced the perception of voice naturalness. Future research may examine how gender-affirming voice therapy can best meet the needs of transmasculine speakers.