Vocal Markers in the Gender Perception of Trans Women and Trans Men

To identify vocal gender markers in trans people, considering the relationship between gender perception and the acoustic and auditory-perceptual parameters of the voice.

Observational, cross-sectional study, approved by the Research Ethics Committee (n. 5.353.501). The judges completed auditory-perceptual judgment (APJ) and acoustic analysis of 30 transgender women and 23 transgender men, aged between 18 and 43 years, based on the production of the sustained vowel /a/ and connected speech (number counting and days of the week). The APJ was made in consensus by two judges; vocal deviation was analyzed using the GRBASI scale; the parameters pitch (high, medium, and low) loudness (strong, adequate, and weak), resonance (laryngopharyngeal, balanced, and nasal), articulation (locked, adequate, and exaggerated), intonation (descending, level, and ascending), and gender perception (feminine, masculine, and neutral). For the acoustic evaluation, the software PRAAT was used to extract the parameters oscillatory frequency (f_o), f_o deviation, minimum and maximum frequency (f_omin/f_omax), first (F₁), second (F₂), third (F₃), and fourth (F₄) formant frequencies. The Kruskal-Wallis test, chi-square test, and Fisher's exact test were used for the statistical analysis of the data. For the regression analysis, the data were analyzed descriptively and inferentially using SPSS 29.0 software. A binary logistic regression model was applied to predict the binary nominal qualitative dependent variable of gender congruence through voice. In all statistical tests, a significance level of 5% (P < 0.05) was used.

The average f_o was 146.289 Hz for trans women and 157.409 Hz for trans men. For trans women, gender perception was related to the parameters pitch (P = 0.013), articulation (P = 0.017), and intonation (P = 0.000). In trans men, gender perception was related to hormone use (P = 0.016), GRBASI tension parameter (P = 0.028), pitch (P = 0.001), loudness (P = 0.033), intonation (P = 0.001), f_o (P = 0.034), f_omin (P = 0.029), f_omax (P = 0.018), and F₁ (P = 0.038). In the results obtained from binary logistic regression for predicting gender congruence based on voice, ascending intonation was an auditory-perceptual predictor (P = 0.001) in the group of transgender women, and F₁ was an acoustic predictor (P = 0.050) in the group of transgender men, both in connected speech.

In trans women, high pitch, adequate articulation, and ascending intonations were observed as markers of female gender. Most of the trans women's voices were perceived as feminine, even when they had a low pitch. In trans men, more tense vocal quality, descending intonations, and average f_o in the range considered masculine were observed as markers of male gender. The parameters high pitch and ascending intonations were markers of female gender for both trans women and trans men. Ascending intonation was an auditory-perceptual predictor of vocal femininity in the transgender women group, and F₁ frequency was an acoustic predictor of vocal masculinity in the transgender men group, both in connected speech.