Some women experience changes to their vocal cords throughout their menstrual cycle, a change brought on by changing hormones. This is especially interesting for female singers, whose livelihood may rely on consistently producing high-quality sounds vocally.

A study with 17 female vocalists in 2017 suggests that there are laryngeal vascular differences that occur throughout the menstrual cycle for fertile women who are not taking hormonal birth control. During a woman’s cycle, the levels of a hormone called progesterone are lowest early on and then highest directly before menstruation. Vocal cord congestion was highest directly before menstruation, when progesterone levels are at their highest.

The study suggests that women who have large differences between their highest and lowest progesterone levels may have noticeable vocalization differences throughout their menstrual cycle. For such women, birth control pills may help to stabilize hormone levels throughout their cycles and so lessen the amount of vocal changes.