Study finds drop in age-related hearing problems

(AP) -- Sweet news for baby boomers: Despite all those warnings that loud rock music would damage their ears, their generation appears to have better hearing than their parents did.

In fact, a new study suggests that the rate of hearing problems at ages ranging from 45 to 75 has been dropping for years, at least among white Americans.

"I'm less likely to have a hearing loss when I get to be 70 years old than my grandmother did when she was 70," said Karen Cruickshanks of the University of Wisconsin-Madison.

She's an author of the study - and a baby boomer who remembers taking guff from her mother for listening to loud music.

Apart from giving her generation some satisfaction, the new work implies that what people do and experience may help them prevent or delay hearing loss as they get older. Experts theorize there may be several reasons for the finding, like fewer very noisy jobs and better ear protection at worksites, immunizations and antibiotics that prevented certain diseases, and maybe even a decline in smoking.

Experts praised the work, but agreed that scientists now must see if the pattern holds up outside of its largely white participants. They also said the result doesn't mean it's safe to blast loud music into your ears from an iPod for hours on end.

Cruickshanks, colleague Weihai Zhan and others reported their work recently in the American Journal of Epidemiology.

They analyzed the results of hearing tests given to about 5,300 people who were at least 45 years old and born between 1902 and 1962. The tests were done between 1993 and 2008, and many participants were tested at five-year intervals. Participants were residents of Beaver Dam, Wis., and their sons and daughters, who lived in a variety of places.

The researchers noted how many tests showed at least mild hearing loss. Then they looked to see if the rate of impairment at given ages was affected by when the person was born.

For example, take the results for men in their early 60s. The impairment rate was 58 percent for men born between 1930 and 1934. For men born just five years later, the rate was about 50 percent. And for men born between 1945 and 1949, the oldest baby boomers, the rate was only about 36 percent.

Overall, for a given age group, men showed on average a 13 percent drop in the risk of impairment for every five-year increase in the date of their birth. For women, the decrease was about 6 percent.

The researchers are now trying to uncover reasons for the decline. Cruickshanks said the explanation will probably be complex and hard to pin down because the pattern has been going on for decades.

But factors could include fewer people with long-term exposure to very loud noise at work, and a decline in smoking, a habit some studies link to ear damage, she said. Maybe changes in health care, including immunizations and use of antibiotics, play some role too, she said.

The study is "very impressive," said Elizabeth Helzner, an epidemiologist who studies age-related hearing loss at the State University of New York Downstate Medical Center in Brooklyn.

The findings make sense in light of declines in long-term exposure to loud noise without ear protection in the workplace and perhaps in hunting and battle, she said. Those exposures would have happened more to men than women, which would help explain why the results were more dramatic in men, she said.

Another possible factor is better control of diabetes and heart disease, both of which are linked to hearing loss, she said.

Now the question is whether the decline will continue with today's young people, who often play loud music in their earbuds for hours at a time, day after day, she said. That chronic exposure may prove more hazardous than the briefer bouts baby boomers had, she said.

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