Effects of Resonance Voice Therapy on Hormone-Related Vocal Disorders in Professional Singers: A Pilot Study

Background: Menstruation-related hormonal alteration can be detrimental to the professional singing voice of women. Resonance Voice Therapy (RVT) has been proven to improve vocal production. However, no research to date has been conducted examining the subjective, acoustic, and stroboscopic effects of RVT on professional female singers having premenstrual or postmenopausal voice disorders. Aim: The aim of this study is to compare the vocal effects of RVT with a control cervical-thoracic intervention in healthy female singers during the premenstrual phase as well as in postmenopausal singers and to evaluate which intervention will allow singers to improve vocal performance regardless of changes in hormonal status. Design: A randomized study was designed for this research. The research subjects were 20 professional female singers from the Southern California area, USA, with 10 premenstrual subjects in one group and 10 postmenopausal subjects in the other group. Among each group, 5 subjects were randomly selected to receive RVT and the remaining subjects received cervical-thoracic–focused exercises. The therapies consisted of 1 month of daily 15-minute sessions. For premenstrual subjects, voice data were collected at days 25 to 27 of the premenstrual phase during a scheduled initial voice evaluation. Follow-up data were collected during the same phase of the menstrual cycle (days 25-27) after 1 month of exercises. For postmenopausal subjects, voice data were collected at an initial voice evaluation with follow-up after 1 month of the assigned voice treatment. Outcomes were assessed with the singer’s voice handicap index (VHI), laryngeal videostroboscopic examination, maximum phonation time (MPT), relative average perturbation (RAP), and pitch range before and following completion of therapies. Alleviation or deterioration percentages were used for statistical analysis. Student t test was used for statistical comparison between therapies. Results: The RVT decreased singer’s VHI for both premenstrual and postmenopausal subjects by an average of 67%, compared with 7.8% for the cervical-thoracic therapy. The RVT also effectively decreased RAP by an average of 57% when combining the premenstrual and postmenopausal groups. The RVT increased MPT and pitch range among both premenstrual and postmenopausal subjects. The stroboscopic examination did not detect any significant differences between the 2 interventions. Conclusions: The RVT is effective for professional fem