Auditory Function Differences Between Women and Men: Is There a Role for the Female Sex Hormones?

Abstract

The thesis aimed to investigate the differences in the fluctuations of the auditory function between pre-menopausal women and age-matched men and whether female sex hormones play a role in these sex differences in the fluctuations of auditory function in women across the short timescale of the menstrual cycle. It also investigates the differences in auditory function fluctuations between post- and pre-menopausal women and whether female sex hormones influence the changes of hearing function across a long timescale (i.e. lifespan) in the post-menopausal women compared to pre-menopausal women. This thesis includes a systematic review and two original research studies using a well-controlled study design and sensitive audiometric tests to assess the whole pathway of the auditory system, and blood analysis of the levels of female sex hormones for the pre- and post-menopausal women at each session. The evaluations of the fluctuations in auditory functions were performed in five weekly sessions for all participants. The research identified a systematic fluctuation in hearing sensitivity in premenopausal women, where age-matched men and post-menopausal women showed stable hearing function across the five sessions spaced one week apart. However, all groups showed no significant fluctuations in speech perception in background noise. Pre￾menopausal women showed improved hearing functions during higher levels of oestradiol, and diminished function during high levels of progesterone, however, speech perception in background noise was not affected by the fluctuations of female sex hormones. This thesis sheds light on how female sex hormones interact with auditory function. By revealing how these hormones affect hearing function, it outlines the way for future research to develop better diagnostic tools and treatments for hearing issues in women.