Altered Formant Feedback Elicits Perceptually Detectable Changes in Vocal Femininity

Purpose: This study examined how cisgender (cis) men and transgender (trans) women respond to altered auditory feedback that shifted formants F1 and F2 down with a magnitude derived from empirically observed comparisons of men's and women's vocal tracts. Pairs of words produced with and without altered feedback were presented to blinded listeners to evaluate whether compensatory changes were associated with a change in perceived femininity. The goal was to investigate whether implicit adaptation to auditory feedback could serve as a strategy in gender-affirming voice training (GAVT). Method: Twenty cis men and six trans women produced word strings while hearing their speech with F1 and F2 shifted down by roughly the magnitude of the average difference between men's and women's formants. Productions were acoustically measured to determine the magnitude of compensatory formant shifts directly opposing the perturbation. Tokens representing the maximum and median degree of adaptation for each participant and vowel were paired with unshifted tokens and presented to 31 blinded listeners, who were asked to select the most feminine production in each pair. Results: Participants exhibited a statistically significant degree of adaptation offsetting the perturbation, averaging 27% of the imposed shift for cis men and 35% for trans women. Listeners selected adapted tokens as “more feminine” with significantly above-chance frequency, roughly 63% of the time. Conclusions: Altered auditory feedback elicited measurable, perceptually detectable changes in resonance associated with gendered voice characteristics. These findings suggest that implicit adaptation to altered feedback could complement explicit resonance training in GAVT, although further study of the acceptability of this method to gender-diverse speakers is essential. Supplemental Material: https://doi.org/10.23641/asha.34701528