Filipa M.B., LãSundberg, JohanHoward, David M.Sa Couto, PedroFreitas, Adelaide2024-05-202024-05-202012-02-011558-9102https://doi.org/10.1044/1092-4388(2011/10-0348)https://hdl.handle.net/20.500.14468/11796Purpose: Difficulties with intonation and vibrato control during the menstrual cycle have been reported by singers; however, this phenomenon has not yet been systematically investigated. Method: A double-blind randomized placebo-controlled trial assessing effects of the menstrual cycle and use of a combined oral contraceptive pill (OCP) on pitch control in singing is presented. Audio-electrolaryngograph recordings were made and blood samples were taken from 9 singers in each of the 3 phases of the menstrual cycle both under the placebo and the OCP conditions for a total of 6 months. Participants sang an exercise consisting of an ascending octave followed by a descending major triad, starting on pitches F4 and B4. Pitch control was assessed in terms of the octave's deviations from pure intonation and of the vibrato rate and extent. Results: Significant differences were found between the 3 phases of the cycle regarding octave size only for pitch F5 during OCP use. Significant vibrato rate differences between placebo and OCP conditions were found only for pitch F5. Conclusion: OCP use may have an effect on pitch control in singers. Possible explanations point to a complex interaction between hormonal milieu and pitch control, enhancing the need for longitudinal studies.enAtribución 4.0 Internacionalinfo:eu-repo/semantics/openAccessartículointonationvibrato ratevibrato extentmenstrual cycleoral contraceptive pill