Quantifying the impact of androgen therapy on the female larynx

To describe the timing of changes in fundamental frequency of the female voice following androgen therapy during female to male gender reassignment.

A 33-year-old female semi-professional singer undergoing gender reassignment and intramuscular androgen injections was examined at monthly intervals to monitor the impact of therapy on the voice. Laryngostroboscopy and acoustic analysis were performed simultaneously to monitor for potential laryngeal pathology.

Pretreatment mean fundamental frequency (MF(0)) was 228.45 Hz and ranged from 140.26 Hz to 430.64 Hz. Between month 3 and month 4 of treatment, MF(0) declined to 116.52 Hz and ranged from 90.75 Hz to 201.07 Hz. Shimmer increased from 3.4% to 7.8%. Noise to harmonics ratio (NHR) also increased from 0.12 to 0.17. The patient has continued to sing semi-professionally despite these changes in laryngeal function.

Androgen therapy exerted a profound change on mean fundamental frequency between the third and fourth months of treatment. In addition, pitch range was reduced in a commensurate fashion. Patients undergoing androgen therapy may undergo a significant change in speaking voice between the third and fourth months of therapy. Moreover, though these changes may exert a profound impact on the singing voice, patients undergoing gender reassignment may still be able to achieve personal and professional success in their singing careers.