Tuesday, October 8, 2002 5:36AM EDT

By DANIEL Q. HANEY, The Associated Press

BEAVER DAM, WIS. -- Naturally, the last thing older folks in Beaver Dam want to hear is that they are going deaf. So 3,753 of them have agreed to regular testing and probing to help people everywhere learn some simple and unexpected things that may ward it off.

Gradual hearing impairment -- long shrugged off as just another inescapable indignity of aging -- is at last getting some serious study, and the results from Beaver Dam suggest something can be done about it after all. Like having a drink, perhaps, or even just going for a walk.

Elderly hearing loss has a fancy name, presbycusis, but surprisingly little is known about what underlies it. Changing this is the goal of the Epidemiology of Hearing Loss Study, the country's largest project devoted solely to the sources of this seemingly universal health problem.

"People need to know that hearing loss might not be an inevitable part of growing older," says Karen Cruickshanks of the University of Wisconsin, the study's director.

Since 1993, her team has measured the hearing and health of two-thirds of all the people over age 48 in Beaver Dam, population 15,000, a modest manufacturing city in the rolling dairy lands about 60 miles northwest of Milwaukee.

If nothing else, the people of Beaver Dam know how good their hearing is, or how bad.

"This settles one thing," says John Landdeck, 61, president of the community hospital and a study volunteer. "Everybody in town knows when they can't hear their wife whether it's their hearing or her mumbling."

That, actually, is one of the study's more interesting findings. It shows that men have poorer hearing than women, even when a lifetime of noisy jobs and hobbies like chain-sawing and snowmobiling are figured in. And as people get past retirement age, their hearing tends to get worse, much worse. Over age 80, about 90 percent of the population has trouble.

If Beaver Dam is typical -- and the researchers think it is -- then hearing loss is considerably more common than most experts would have guessed. The usual national estimate is that one-third of older Americans have some degree of problem. This study puts the figure at nearly half.

Complicated answers

But even if more whadya-say moments are hard to avoid, Cruickshanks hopes her study will find ways to delay the problem or keep it as mild as possible. Although the hazards of incessant loud noise are well known, this study is beginning to show the effects of other less obvious health and living habits, including some that people can change.

"It's a very complicated subject," says Dr. James Battey, director of the National Institute on Deafness and Other Communication Disorders. "A lot goes into it, and we are only beginning to sort it out."

Like drinking, for instance.

Beaver Dam people who have a drink or two a day are about 40 percent less likely than nondrinkers to have hearing loss, although heavy drinking is bad for the hearing, just as it is for other parts of the body. Exercise also seems to prevent or delay elderly hearing loss.

On the other hand, smoking seems to be bad for the hearing. In Beaver Dam, smokers are about 70 percent more likely than nonsmokers to have some hearing loss. Even passive smoking appears to increase the risk.

All of this raises the intriguing possibility that what's good for the heart -- or bad for it -- may have similar effects on the hearing. Clogged arteries are the underlying cause of heart attacks, and the researchers suspect that decreasing blood flow to the inner ear increases the risk of going deaf.

They found that heart attack survivors are almost twice as likely to have poorly working cochleas, the spiral-shaped organs in the ears that convert vibrations into nerve impulses. And those whose hearing worsened during the study tended to have more thickening of the carotid artery, another sign of clogging.

If preventing heart disease also saves hearing, it might offer another reason to take cholesterol-lowering drugs called statins. So the researchers are watching the Beaver Dam residents who use the pills.

Still, none of this proves a real link between bad hearts and bad ears. Researchers outside the Beaver Dam project are divided on the subject.

While that debate plays out, the older folks of Beaver Dam cannot help being more aware of their hearing and what harms it.

Helen Glewen, 61, a retired nurse, says that since joining the study, she has convinced her husband, Claryn, to wear earplugs when he hunts. And she has changed her seat at the Dodge County Fair's country music shows.

"I used to take a lawn chair and sit as close as I could," she says. "Now I sit way up in the bleachers."

Certainly noise is the most obvious cause of bad hearing. People tend to have worse hearing later in life if they drove tractors without cabs, served in tanks in World War II or had any job where they needed to shout to be heard. Loud hobbies such as guns and woodworking also can damage hearing.

Despite Mrs. Glewen's worry about country music, the researchers conclude that concertgoing is not much of a factor.

-- Anonymous, October 08, 2002