Despite all the Walkmen, boomboxes, 8-tracks, iPods and Bluetooth headsets that have delivered raucous noise to the ears of Baby Boomers, hearing loss appears to be declining among adults.

This counterintuitive finding from the first study of long-term changes in hearing loss is that for every five years a man or woman was born later in the 20th century, their chance of having hearing impairment dropped 13 percent and 6 percent, respectively.

A key suggestion of the report is that other, positive changes in the last 50 years — reduced noise levels at work and better overall health — are more important than the rise of headphones and other entertainingly noisy new products.

"Because many people think that the world is getting noisier and noisier, they think that the prevalence of hearing impairment might increase," said Weihai Zhan, a population health scientist at the University of Wisconsin, Madison. "But the prevalence of hearing impairment is decreasing across the generation."

The new work draws on a long-term study of health outcomes for the people of Beaver Dam, Wisconsin, a small town in between Milwaukee and Madison. More than 2,000 people underwent three health screenings at five-year intervals.

The study also underscores that hearing loss clearly is not wholly determined by genetic factors or simple aging, but rather stems from several "environmental, lifestyle or other modifiable factors," the authors wrote in their new paper in the American Journal of Epidemiology January issue.

Image: ElDave/Flickr

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