March 1, 2008 Otology research shows that many teens and adults set their headphones at volumes that can cause hearing damage. Listeners set their headphones at a preferred volume, then place them on a mannequin equipped with an in-ear microphone. Measuring the volume of the headphones allows the researchers to help listeners find a safe volume level. Exposure to excessively loud sounds damages the stereocilia in the inner ear, and repeated exposure can cause hearing loss.
Do you know how loud that music is your child is listening to? You probably don't and you probably don't know it could be loud enough to permanently damage their hearing. But one young woman is getting her peers to listen to her message about dangerous decibels.
With the generation that's plugged-in 24/7 a parent might never have to yell, "Turn that music down!" The Centers for Disease Control report a growing number of children, nearly 13 percent, have noise-induced hearing loss.
Hearing experts say 85 decibels is safe -- which is the sound of busy city traffic -- but too many teens are turning up the volume. When college sophomore Genna Martin realized the potential perils of personal music players, she decided to do something about it. She created "Jolene" -- donning the electronic mannequin with a blue wig, shades and leather.
"I thought it was a cool idea and a good way to attract attention," says Martin.
Jolene's equipped with a microphone in her ear and attached to her is a sound meter. Genna invites kids to hook up their IPod's and get a decibel reading. Then Genna tells them if that volume level is safe or not … "ninety-nine."
At that decibel level, nineteen-year-old Rachel Caldwell-Powell can safely listen for only fifteen minutes. "I think I'll be more conscious of it," says Caldwell-Powell. Still for some, volume is as important as lyrics. "It's nice to have the level up there. You're getting all the nuances of the music," says nineteen-year old Daniel Creamer.
But Genna Martin has a warning for those in her generation who crank it up. "If you listen to it this loud now, by the time you're forty you won't be able to hear it anymore," says Martin.
And it's tough to tuck earbuds in your ears, if they're already fitted with hearing aids. One good rule of thumb -- if you can hear sound leaking out the earbuds, the volume is probably too high to be safe.
RECOMMENDED LEVELS: The more often and the louder you player your player, the more likely you'll experience some hearing loss. To come up with recommended listening times and sound levels, the researchers compared the players' volume levels to the minimum sound level for the risk of hearing damage: 85 dBA. Typically, a person can tolerate about two hours of 91 dBA per day before risking hearing loss. The researchers recommend listening to iPods for -- hours a day with earphones if the volume is at 80% of maximum levels. Listening at full volume is not recommended for more than 5 minutes per day using the earphones that come with the player.
ABOUT HEARING LOSS: Loud sounds stress and could damage the delicate hair cells in the inner ear that convert mechanical vibrations in the air (sound) into the electrical signals that the brain interprets as sound. If exposed to loud noises for a long time, the hair cells can become permanently damaged and no longer work, producing hearing loss. Noise-induced hearing loss can be caused by two types of noise: sudden bursts, such as firearms or fireworks; or continuous exposure to loud noise, such as motorized recreational vehicles, loud sporting events, power tools, farming equipment, or amplified music. For a person to lose their hearing because of continuous exposure, it would depend on how loud the sound was and how often and for how long they heard it. It takes repeated exposures over many years to cause a noise-induced hearing loss in both children and adults.
The Acoustical Society of America contributed to the information contained in the video portion of this report.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.