Effect of danazol on vocal pitch: a case study

Acoustic analysis was used to measure fundamental frequency (vocal pitch in cycles per second) in a woman before, during, and after danazol therapy for endometriosis. A moderate lowering of fundamental frequency occurred within the three months of therapy and progressively lowered throughout the 5.5-month course. There was some action toward pretreatment levels, but 12 months after therapy, lowering of fundamental frequency persisted. The acceptability of this side effect and the need for further research are discussed.