Still loud and clear

DESPITE the advent of iPods, ever-louder movies and other massive audio changes in society and technology, American adults’ hearing remains about the same as it was 35 years ago, according to a new report.

The study, presented this month at a meeting of the Acoustical Society of America, also found that darker-skinned people tend to hear better. Non-Hispanic black adults in the U.S. have, on average, sharper hearing than Mexican Americans, and both groups hear better than non-Hispanic whites. Women, in general, hear better than men.

More than 5,000 adults, ages 20 to 69, were tested for their “hearing thresholds” -- the softest sound one can hear -- over a range of frequencies. The results, which were then compared with a study conducted 35 years ago, were a surprise because most people “have the perception that the world is getting to be a noisier place,” said study coauthor Christa Themann, an audiologist. Overexposure to noise is linked to hearing impairment.

“More people use hearing protection devices, and that may have had some effect,” speculated study coauthor William Murphy, a physicist for the National Institute for Occupational Safety and Health, which sponsored the study. Also, he said, fewer Americans work in loud factory jobs than 30 years ago.

But, the authors said, it may also be too early to detect the hearing loss caused by a louder society because people lose their hearing gradually.