Effects of Intensive Intonation Training in Transgender and Gender Diverse People Aiming for a More Feminine-Sounding Voice: A Randomized Clinical Trial

Purpose: The aim of this randomized clinical trial was to investigate the effect of intonation training in transgender and gender diverse (TGD) persons aiming for a more feminine-sounding voice on acoustic (intonation) parameters, listener perceptions, and self-reported outcome measures. Method: Thirty TGD individuals presumed male at birth with an aim of developing a more feminine-sounding voice were included and were randomly allocated to two groups. Group 1 received 4 weeks of intonation training. Group 2 received 4 weeks of intonation training after 4 weeks of sham training. Participants were recorded three or four times: baseline (before sham training; only Group 2), pre (before intonation training), Post 1 (after intonation training), and Post 2 (after 4 weeks of no intervention). Both acoustic and perceptual outcome measures were examined and analyzed using linear mixed models. Results: Statistically significant increases were found for all acoustic intonation parameters. In addition, significant increases were found for the fundamental frequency values (median, percentile [pc] 25, and pc 75). The listening experiments showed a significant increase in femininity ratings and increases in all perceptual intonation parameters. Participants perceived that their voice was more in line with their gender identity, but they still needed voice and communication training (VCT). Conclusion: Positive acoustic and perceptual effects were found after intonation training in TGD people aiming for a more feminine-sounding voice, which adds to the evidence that intonation can be a beneficial aspect of VCT for TGD individuals. Supplemental Material: https://doi.org/10.23641/asha.28611542