Transmasculine Voice Modification: A Case Study.

This case study measured the effects of manual laryngeal therapy on the fundamental frequency (fo), formant frequencies, estimated vocal tract length, and listener perception of masculinity of a 32-year-old transmasculine individual. The participant began testosterone therapy 1.5 years prior to the study. Two therapy approaches were administered sequentially in a single session: (1) passive circumlaryngeal massage and manual laryngeal reposturing, and (2) active laryngeal reposturing with voicing. Acoustic recordings were collected before and after each treatment and 3 days after the session. Speaking fo decreased from 124 Hz to 120 Hz after passive training, and to 108 Hz after active training. Estimated vocal tract length increased from 17.0 cm to 17.3 cm after passive training, and to 19.4 cm after active training. Eight listeners evaluated the masculinity of the participant's speech; his voice was rated as most masculine at the end of the training session. All measures returned to baseline at follow-up. Overall, both acoustic and perceptual changes were observed in one transmasculine individual who participated in manual laryngeal therapy, even after significant testosterone-induced voice changes had already occurred; however, changes were not maintained in the follow-up. This study adds to scant literature on effective approaches to and proposed outcome measures for voice masculinization in transmasculine individuals.