Effectiveness of testosterone therapy for masculinizing voice in transgender patients: A meta-analytic review

ABSTRACT

Background: Testosterone therapy is the predominant treatment for voice masculinization in transgender patients. Although lowering of voice fundamental frequency (f₀) occurs with testosterone therapy, evidence suggests voice and gender identity may not fully align—i.e., voice-gender congruence may not be achieved—with its use.

Aim: This meta-analytic review evaluates the effectiveness of testosterone therapy to masculinize voice in transgender patients.

Methods: Multiple electronic databases were queried (inclusion dates: from database inception up to October 27, 2017) to identify original research on voice masculinization using testosterone therapy. Nineteen articles were included in this meta-analytic review, which followed PRISMA guidelines. In addition to qualitative analyses, random effects proportion meta-analyses were performed on data related to f₀, voice-gender congruence, voice problems, and satisfaction with voice.

Results: A meta-analysis on f₀ data showed after 1 year of testosterone therapy a combined estimate of 21% of participants (95% confidence interval [CI]: 5%–43%; I²: 59.9%) did not achieve cisgender male normative frequencies (f₀ ≤ 131 Hz). Meta-analyses on incomplete voice-gender congruence and voice problems indicated combined estimates of 21% (95% CI: 10%–34%; I²: 0.0%) and 46% (95% CI: 14%–79%; I²: 90.2%), respectively. Regarding incomplete satisfaction with voice, a meta-analysis showed a combined estimate of 16% (95% CI: 7%–28%; I²: 0.0%).

Discussion: We found that not all transgender patients using testosterone therapy to masculinize voice should expect f₀ lowering to cisgender male normative frequencies after 1 year. The vocal transition may involve voice problems for many patients, and some might not achieve voice-gender congruence without additional, voice-specific intervention. Given these findings, a voice evaluation should occur prior to initiating testosterone therapy and involve counseling on expectations for voice. Transgender patients who pursue voice masculinization may need management from laryngology and speech and language therapy to improve voice-gender congruence, mitigate voice problems, and increase satisfaction with voice.

KEYWORDS:

• Gender identity
• gender attribution
• patient satisfaction
• testosterone therapy
• transgender
• voice-gender congruence
• voice problems

Acknowledgments

The authors thank Laura Zeigen, M.A., M.L.I.S., M.P.H., A.H.I.P., Assistant Professor and Librarian at Oregon Health & Science University, for her assistance with electronic database queries to identify articles. The first author (AZ) thanks several colleagues for their thoughtful feedback on the manuscript: OHSU NW Center for Voice and Swallowing Director Donna Graville, Ph.D., CCC-SLP, OHSU Research Development & Academic Communications Director Rachel Dresbeck, Ph.D., and OHSU Transgender Health Program Director Amy Penkin, M.S.W., L.C.S.W. Finally, the authors are grateful for the transgender perspective of Jackson Roux-Brown, B.S. and M.S.W. Candidate, who approved the final draft of this manuscript.

Author contributions

Study concept and design: Ziegler, Henke, Wiedrick; Acquisition of data: Ziegler, Henke, Wiedrick; Analysis and interpretation of data: Ziegler, Henke, Wiedrick; Drafting of the manuscript: Ziegler, Henke, Wiedrick, Helou; Critical revision of the manuscript for important intellectual content: Ziegler, Helou.

Conflict of interest

Leah B. Helou, PhD, CCC-SLP has received a portion of registration fees for continuing education courses that she planned and instructed on the topic of transgender voice. The other authors declare that they have no conflicts of interest.

Note

Notes

1. In this review, we refer to binary and nonbinary patients who seek to align voice and gender identity collectively as transgender patients. With improvement in third party payer reimbursement for speech and language therapy services related to voice masculinization, we use the terms “patient” and “voice therapy” but are aware some individuals prefer the terms “client” and “voice training”. Finally, we use the term masculinization to describe the vocal transition of transgender patients designated female at birth because of its ubiquity in the literature. However, we feel the term masculinization underscores a 2-category system of gender identity and prefer to describe vocal behaviors in relation to a transgender patient's goal for vocal representation of gender identity: authentic vocal expression that affirms their gender identity, which may include nonbinary representations of gender.

Additional information

Funding

Oregon Health & Science University Otolaryngology Departmental funds.