Longitudinal Case Study of Transgender Voice Changes Under Testosterone Hormone Therapy

Area of Science:

• Otolaryngology
• Speech-Language Pathology
• Endocrinology

Background:

• Cross-sex hormone therapy, specifically testosterone, is a key component of medical transition for transgender men.
• Voice and speech changes are anticipated effects of testosterone therapy, but detailed documentation is limited.

Observation:

• A comprehensive case study tracked voice and speech in one healthy 30-year-old transgender male over one year of testosterone therapy.
• Data included acoustics, aerodynamics, and laryngeal function, with testing at multiple timepoints.
• Acoustic and perceptual analyses assessed pitch, loudness, voice quality, vocal tract length, and perceived gender.

Findings:

• Speaking fundamental frequency (f_o) decreased from 183 Hz to 134 Hz.
• Phonatory frequency range shifted from D#3-E6 to A2-A5.
• Naïve listeners perceived speech as male after 37 weeks; voice quality showed no negative changes.

Implications:

• This study provides detailed insights into the multifaceted voice and speech modifications during testosterone therapy.
• Findings contribute to a better understanding of vocal changes in transgender men, extending beyond fundamental frequency.
• The comprehensive data can inform clinical practice and patient counseling regarding vocal outcomes of hormone therapy.