Is your hearing really getting worse, or are you just imagining things? The Harvard Medical School offers some tips for evaluation

Does it seem that many people mumble? Do you resort to nodding to pretend to understand people when you hardly heard a word they said? Do your kids or grandchildren complain that you turn the volume up too loud on the TV? If you answered yes to most of these questions, you could benefit from a hearing evaluation.

Hearing ability decreases with age. As men age, their hearing deteriorates slightly more than women’s, and the hearing of white people gets worse than that of blacks or Hispanics. Young people are affected, too. In a 2006 survey commissioned by the American Speech-Language-Hearing Association (ASHA), more than half of high school students had symptoms of hearing loss, such as ringing in the ears and trouble following conversations.

Causes of hearing loss

Hearing loss has many causes, including genes, birth defects, and side effects from medication, but the cause of about one-third of cases of hearing loss is avoidable: routine exposure to very loud noise. Jackhammers, lawn mowers, and airplanes are obvious sources, but other culprits are hair dryers, portable music players, and other gadgets that have become part of the fabric of everyday life. In ASHA’s survey, 13% of the high school students said they set the volume of their MP3 players very loud, a habit that may lead to permanent hearing loss. Loud noise degrades the sensory cells in the ear, cells that don’t grow back. Similarly, if you loved to blast the rock ’n’ roll decades back, you may now be experiencing the effects of that damage.

Help for your hearing

The good news is that recent advances in hearing technology have made

How Loud Is Safe? Protect your ears from sounds louder than 80 decibels.
Decibels	Sounds
20	Watch ticking
30	Whispering
40	Leaves rustling, refrigerator humming
50	Neighborhood street, average home
60	Dishwasher, normal conversation
70	Car, alarm clock, city traffic
80	Garbage disposal, noisy restaurant, vacuum cleaner, outboard motor, hair dryer
85	Factory, screaming child, portable stereo at high volume
90	Power lawn mower, highway driving in a convertible
100	Diesel Truck, subway train (outside, not as a passenger), chain saw
120	Rock concert, propeller plane, portable stereos on maximum volume
130	Jet plane (100 feet away), air-raid siren
140	Shotgun blast, explosion
Sounds of 80 dB or less are believed to be safe for nearly all healthy adults, no matter how long you hear them. Sounds of 91 dB should be limited to no more than two hours for a healthy adult. Limit 100dB sounds to 15 minutes and 120 dB sounds to about nine seconds. The long-term effects of high noise levels for children are unknown; therefore, the thresholds cited here may be too high for them.

hearing aids smaller and barely noticeable. They also do a better job of boosting the sounds you want to hear and eliminating the ones you don’t, like the background noise in a restaurant. Hearing aids make it possible to pick up spoken words clearly, to follow dialogue in movies and plays, and to enjoy music where once there were only muffled tones. If you are not a candidate for a hearing aid, you may be helped by one of the implantable devices now available.

Down the road, hearing aids may no longer be needed. The recent discovery of genes that prevent hair cell regeneration has spurred experiments with gene therapy techniques that regrow hair cells. These techniques may one day be able to reverse hearing loss.

Of course, it’s best to prevent hearing loss from occurring in the first place. But even if you already have some hearing loss, it’s not too late to prevent further damage. Wear earplugs when using noisy equipment. Moderate the volume on your stereo. And pass along this information to your children and grandchildren to help keep their world sounding crisp and clear.