Fundamental frequency outcomes after type III thyroplasty in cisgender men: a prospective cohort study

Persistent high-pitch voice in cisgender men can cause functional and psychosocial burden, and Type III thyroplasty is widely used to lower fundamental frequency (F0). Prospective data with standardized recordings and explicit estimates of F0 change are limited. This study quantified postoperative F0 change and examined whether it depended on elapsed days between recordings. In a prospective single-center cohort, cisgender men undergoing Type III thyroplasty completed standardized smartphone recordings of sustained /a/ before surgery and at a single postoperative visit. F0 from a 3-s mid-segment was extracted in Praat. Pre- and postoperative F0 were compared with a paired-samples t-test (ΔF0 = post − pre). Linear regression tested the association between ΔF0 and elapsed days between recordings. Of 89 patients with a preoperative recording, 33 (37.1%) provided a postoperative sample. Mean F0 decreased from 123.32 Hz (SD 23.76) to 107.58 Hz (SD 19.15); the mean paired difference was ΔF0 = − 15.74 Hz (95% CI − 23.72 to − 7.76, p < 0.001). Postoperative recordings occurred a median of 254 days after the preoperative recording (IQR 182–344). ΔF0 was not associated with elapsed days (β = −0.016 Hz/day, p = 0.424, R² = 0.020). No intra- or postoperative complications were observed. Type III thyroplasty in cisgender men yields a moderate, clinically interpretable reduction in F0 that appears robust to variation in postoperative timing. These estimates provide quantitative benchmarks for postoperative counseling and support standardized smartphone recordings in future outcome studies.