Madison, Wisconsin - Despite dire predictions about listening to loud music, members of the rock 'n' roll generation are aging with much better hearing than their parents had at the same age.
In the first large-scale study of the hearing of 5,275 adults born between 1902 and 1962, researchers from the University of Wisconsin School of Medicine and Public Health showed that baby boomers are holding on to good hearing longer than their parents did.
"Generally people think that our world is getting noisier and noisier, but we found that the prevalence of hearing loss is decreasing," says Dr. Weihai Zhan, who led the study. "These results suggest that hearing loss is not a normal part of aging and there are things we can do to delay hearing loss."
The study showed hearing impairment rates were 31 percent lower in baby boomers across all age groups. For example, in the group of men now in their early 60s (those born between 1944 and 1949), 36.4 percent had a hearing impairment;among men born between 1930 and 1935, 58.1 percent had a hearing impairment at the same age.
The older generation was part of the Epidemiology of Hearing Loss Study, which has been tracking hearing loss in volunteers from the community of Beaver Dam, Wisconsin, since 1993. Starting in 2005, researchers began testing the hearing of adult children, as part of the Beaver Dam Offspring Study. Both studies are funded by the National Institute on Aging (NIA), part of the National Institutes of Health.
"These two long-term population studies provide important evidence that age-related hearing loss is not inevitable," said Dr. Wen Chen, of the NIA Division of Neuroscience. "These encouraging findings should spark future research to help us better understand the factors that favor preservation of hearing function, and that will allow development of strategies to prevent hearing loss and the associated functional declines in older adults."
If baby boomers lost their hearing at the same rate as their parents did, about 65.5 million Americans would be hearing-impaired by 2030;this new study suggests the number is likely to be closer to 50.9 million.
"Contrary to what our parents thought, we didn't lose our hearing from listening to transistor radios in the '60s, boomboxes in the '80s or iPods in the last decade," says Dr. Karen Cruickshanks, UW School of Medicine and Public Health professor of population health sciences and ophthalmology and visual sciences.
One reason, Cruickshanks says, is that hearing loss from one-time exposures such as music at a loud concert tends to be temporary.
"Evidence suggests that short-term exposure leads to temporary hearing loss," she says, "but it's the day-to-day exposure that leads to more permanent hearing loss."
Other factors could include stricter rules about workplace noise exposure, and fewer members of the younger generation working in noisy workplaces such as mining and manufacturing.
Reduced smoking rates in younger generations should result in less chronic cardiovascular disease, which can cause hearing loss. And, because infection and inflammation are also associated with hearing loss, Cruickshanks says, "Better health care and the widespread use of antibiotics may also be part of the explanation."
The good news is that hearing loss doesn't need to accompany aging.
"If hearing loss was genetically determined, you wouldn't see this loss over a generation," she says. "It's exciting to know that there are things we can do to prevent or delay hearing loss."
The study is being published in the Jan. 15 edition of the American Journal of Epidemiology.
Cruickshanks says the researchers want to thank the "fantastic" people of Beaver Dam, who have participated by the thousands in long-running studies of vision, hearing and other aging topics since 1988.
Taken from www.med.wisc.edu/news.
