Examinando por Autor "Ledger, William L."

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  • Miniatura
    Publicación
    A case-study on the effects of the menstrual cycle and the use of a combined oral contraceptive pill on the performance of a western classical singer: an objective and subjective overview
    (SAGE, 2007-07) Howard, David M.; Davidson, Jane; Ledger, William L.; Jones, Georgina; Filipa M.B., Lã
    This article reports the results of a case study on the effects of the menstrual cycle and the use of a third generation oral contraceptive pill (OCP) on the pattern of vibration of the vocal folds of a young classical female singer when singing a Lied by Schumann, Widmung. The electrolaryngraphically derived closed phase quotient (CQ) was used as a measure of vocal control across the menstrual cycle for both OCP and placebo use. This was a double blind randomised placebo controlled trial. Neither the researchers nor the participants were aware of which arm of the study would come first. A total of six audio-recordings and six blood samples were performed at three specific stages of the menstrual cycle, for both OCP and placebo use: at menstruation, and during follicular and luteal phases of the menstrual cycle. Results indicate that the use of a third generation OCP diminishes differences between the distributions of closed quotient across the menstrual cycle by dampening fluctuations of steroid hormones. It seems that the singer was able to improve vocal control across the menstrual cycle when she was using an OCP with antimeneralocorticoid and antiandrogenic properties.
  • Miniatura
    Publicación
    Oral contraceptive pill containing drospirenone and the professional voice: an electrolaryngographic analysis.
    (Taylor & Francis, 2009-07-11) Filipa M.B., Lã; Howard, David M.; Ledger, William L.; Davidson, Jane; Jones, Georgina; Filipa M.B., Lã
    Few studies have been concerned with the effects of combined oral contraceptive pills (OCP) on those who use their voices as a tool of trade. A cohort study involving 20 female professional voice users was carried out assessing irregularity of vocal fold vibration, based on: 1) period-to-period frequency peaks (CFx), and 2) period-to-period amplitude peaks (CAx) in the cycle-to-cycle excitation of the vocal tract. These vocal measures and blood samples were collected at three points of the menstrual cycle, for both natural and OCP cycles. No significant differences were found in vocal parameters assessed between the natural and OCP cycles. The intake of this OCP was not found to have a systematic effect on the vocal parameters studied. Based on these results the modern OCP preparations can be considered safe medications which do not have a negative effect on voice quality in professional voice users.
  • Miniatura
    Publicación
    The effects of a third generation combined oral contraceptive pill on the classical singing voice
    (Elsevier, 2007-11) Filipa M.B., Lã; Ledger, William L.; Davidson, Jane; Howard, David M.; Jones, Georgina; Filipa M.B., Lã
    The success of professional operatic singers depends upon the quality of their vocal mechanism. This is known to be sensitive to changes in the endocrine environment. Despite a widespread belief among singers that vocal quality changes according to the stage of the menstrual cycle, this has received little attention. In particular, the possibility that use of the contraceptive pill might stabilize vocal quality by ‘‘dampening’’ hormonal fluctuations has not previously been studied systematically. Here, we show that drospirenone containing oral contraceptive pill (Yasmin, Schering AG, West Sussex, UK) with antiandrogenic and antimineralocorticoid properties demonstrates a significant reduction in the irregularity of the pattern of vibration of the vocal folds during the performance of highly trained classical singers. This study constitutes the first double blind, randomized placebo controlled trial to assess the effects of the contraceptive pill on the patterns of vibration of the vocal folds during the performance of Western classical singing repertoire.