A Comparison of Prosody Characteristics Before and After Gender-Affirming Vocal Feminization Therapy

Background: Gender-affirming voice therapy includes a variety of techniques to help better align voice with the patient’s gender identity. Some techniques for vocal feminization include, but are not limited to, pitch and resonance training, as well as intonational pattern changes. However, there is limited research on how measures of prosody contribute to the feminization of the voice. This study aimed to measure prosodic vocal changes in patients who completed vocal feminization therapy.

Methods: Patients were recruited from the University of Cincinnati Voice Center where they completed voice recordings of the second and third sentences of the rainbow passage before and after vocal feminization therapy. The acoustic outcome measures of the study included: i) Fundamental Frequency (f0): median, interquartile range (IQR), and percentage of words produced with glottal fry; ii) Speech Rate: syllables per second, number of pauses, and average duration of pauses (ms); iii) Vowel Characteristics: duration and intensity (dB SPL) of stressed vowels. Paired t-tests were calculated to compare measures before and after therapy.

Results: Preliminary results from 16 patients (15 transgender women, 1 non-binary person, Mean Age = 31 +/- 9.4 years) revealed a significant increase in median f0 from 131 Hz to 184 Hz (p .05). The percentage of words spoken with glottal fry was reduced from 11% to 6%, approaching significance (p = .07). Vowel duration and vowel intensity analyses are ongoing.

Conclusion: Enrollment in this study is ongoing. Preliminary results suggest that vocal feminization therapy effectively increases vocal pitch while potentially reducing the usage of glottal fry. However, characteristics related to speech rate and pausing were unchanged. Further analyses will be completed to identify other areas of prosody related to vocal feminization.