By Christopher Geissler, Ph.D.
While the anatomy of the inner ear does not vary much among individuals, differences in hearing and hearing loss in men and women are well documented. A recent review of these differences by Benjamin Z. Shuster, Didier A. Depireux, Ph.D., Jessica A. Mong, Ph.D., and Ronna Hertzano, M.D., Ph.D., a member of the Hearing Health Foundation’s Hearing Restoration Project, appeared in the June 2019 issue of the Journal of the Acoustical Society of America.
Surveying the existing literature, the authors summarize what is known about estrogen’s role in protecting against or lessening the effects of hearing loss. Estrogen is a hormone present in all human beings but in higher levels generally in individuals who identify as female.
Documented sex differences include better outer hair cell function and more prominent auditory brainstem response in women. Women also have lower rates of hearing loss than men, and men also experience declines in hearing more rapidly than their female counterparts.
There is substantial evidence that estrogen plays a role in these differences, which is unsurprising, given that sex hormones are often behind physiological differences between the sexes. Studies demonstrate that estrogen helps determine hearing ability and can protect hearing over time.
But despite ample evidence of estrogen’s role in hearing, scientists are still not entirely sure how it works. Further research on estrogen and hearing will help scientists develop treatments for age-related and noise-induced hearing loss.
A better understanding of estrogen’s role in hearing and differences between the sexes is also important because, as the authors point out, “a large sex bias still exists in many aspects of hearing research,” which means that studies that involve only men or that do not account for sex at all could lead to the development of treatments that will be less effective for women.
Christopher Geissler, Ph.D. is Hearing Health Foundation (HHF)’s director of program and research support. Ronna Hertzano, M.D., Ph.D., is a member of HHF’s Hearing Restoration Project consortium based at University of Maryland School of Medicine.