Effect of the menstrual cycle on laryngeal muscle tension of singers and nonsingers

Abstract

Intrinsic laryngeal muscular tension was evaluated by means of electroglottography and laryngostroboscopy in 20 singers and 20 nonsingers every other day for two menstrual cycles. A laryngograph, an oscilloscope, a computer, a sound pressure level meter, and a laryngostroboscope were used for this research. It was revealed that ovulation did not change muscular tension in all subjects. Hypotension was found in both singers and nonsingers. In singers it appeared often in different segments of the cycle, in nonsingers it appeared seldom around menses only. Possible explanations are: muscle hypotension appeared in consequence of laryngeal water retention and edema of vocal folds as a result of the drop in estrogen and progesterone secretion and fluctuation in these hormone levels. It was concluded that compensation for hypotonus required effort and could be a reason for the begining of voice disorders.