Auditory-Perceptual Assessment and Acoustic Analysis of Gender Expression in the Voice

Determine if acoustic measurements exist that are predictive of Auditory-Perceptual Assessment (APA) of gender expression in the voice of transgender, nonbinary, and cisgender Brazilian speakers by transgender, nonbinary, and cisgender judges, as well as speech-language pathologists in the area of voice studies.

Cross-sectional study. Clips of speech (automatic speech and expressive reading of poetry) and sustained vowel emission of people of different genders were recorded and underwent APA for gender expression in the voice using a visual analog scale across 100 points, ranging from very masculine to very feminine. Sixteen acoustic measurements were extracted (noise, perturbation, spectral, and cepstral measurements). A descriptive and inferential analysis was performed using interclass coefficients of correlation and stepwise multiple linear regression, considering P < 0.05 for statistical significance.

Forty-seven people of different genders had their voices recorded. The perceived gender of these voices was judged by 236 people (65 speech-language pathologists, 101 cisgender people, and 70 transgender and nonbinary people). The perceptions and measurements that were predictive of gender perception in the voice differed according to the task (vowel or speech) and the group of judges. The predictive acoustic measurements that were common in all groups were: speech-median F0, harmonic-to-noise ratio (HNR), F0 standard deviation (F0sd), average width between F0 peaks, and spectral emphasis (Emph); vowels-median F0, HNR, F0sd, and average width between F0 peaks. Divergent measurements between groups were: speech-coefficient of variation of intensity, speech rate (Sr), minimum and maximum F0, jitter, and shimmer; vowels-coefficient of variation of intensity, Emph, Sr, and minimum and maximum F0.

There are acoustic measures that may predict APA; however, each group of judges considers different measures to evaluate gender, revealing an important influence of context on the evaluator in gender assessment through the voice.