Gender-expansive listeners invite us to reconsider voice categorization as a simple matter of pitch and timbre

Past literature has focused on pitch and timbre cues as the main determinants of the voice of an actor (a speaker or a singer). But in real life, judges rely on non-auditory cues such as the actor’s facial features, height, body size and shape. Resisting these visual biases could provide more accurate assessment of a voice but requires a stronger dissociation between auditory attributes and physical appearance, an ability hypothetically acquired by gender-expansive participants. In three online studies, we examine Faching (allocating voices into traditional categories). In study 1, 166 participants (85 cis, 81 gender-expansive) rated 144 audio (A) samples from 18 different actors (3 from each major Fach category, excluding countertenor) along a slider labeled low/dark to high/bright. Participants then guessed the voice types of the same actors in silent videos (V), before rating them in AV combinations. The cis group exhibited 30% more visual bias than the gender-expansive group. To further understand how gender-expansive participants obtain this benefit, we manipulated the fundamental frequency (in study 2) or the vocal tract length (in study 3) by ± 3 semitones from the original stimuli. Preliminary findings suggest that the two groups differ in the face of timbre but not pitch manipulations.