September 13, 2010
By Claire McCarthy, M.D.
Boston Children's Hospital
If you have children in middle school or high school, chances are they spend some portion of their day with earphones in their ears.
It's become so common that we hardly even notice it except, maybe, when we call to them and they don't hear us. "You are going to damage your hearing with those," we say once we get their attention. But if you're like most parents, you don't do much more than that.
It's time to start doing more.
A recent study published in the Journal of the American Medical Association found that one out of five adolescents (ages 12 to 19) has some evidence of hearing loss. This is a 31% increase over the last 15 years. Most of that hearing loss was slight, but 1 in 20 adolescents had more than slight hearing loss; this was a 77% increase over the same time period.
We don't know exactly why this is happening. Exposure to loud noises is most likely a factor. Noises that are too loud and that last for too long damage tiny sensory hair cells in the inner ear. This is called noised-induced hearing loss (NIHL) and it is permanent. (Read more about it at the Noisy Planet website.
Listening to music on MP3 players can be the equivalent of listening to very loud noises. A European study showed that people who listen to their MP3 players for just five hours a week at high volume settings exposed themselves to more noise than permitted in the noisiest factory or workplace.
And for those whose say, oh, we don't put the volume up that high, here's another interesting study: Researchers in Sydney, Australia randomly stopped people on the street and checked to see how loud they played their MP3 players. They found that one in four listened at volumes that were similar to small power tools, which could cause long-term hearing damage.
France recently limited the maximum volume of an iPod touch® to 100 decibels. Here in the United States, it's somewhere around 120 decibels, which, for comparison, is about equivalent to a jet plane taking off. Many kids listen at volumes greater than 85 decibels. This is the level at which the Occupational Safety and Health Administration (OSHA) requires workplaces to have noise-monitoring programs. Why? Prolonged exposure to noise above 85 decibels can cause hearing loss.
The effects may not show up for years, which contributes to our complacency. But it's time to change that. We warn our children that smoking can lead to cancer later in life. We tell them to eat their vegetables. And we tell them to exercise to prevent heart disease later in life. So we need to let them know that blasting the iPod now could seriously affect their hearing in a few short years.
You know it's too loud if:
- You can hear the music, even though they have earphones in
- They can't hear a normal conversation happening near them
Here are a few things parents should know and do:
- Discourage the use of earbud earphones. These are the most popular, but by fitting into the ear canal they can increase the sound levels by up to 9 decibels (the difference between an alarm clock and a lawnmower). And because they let more outside noise in, kids are more likely to turn up the volume. Look for ones that fit softly over the whole ear. (You'll get push-back, as they are bigger and kids don't think they are cool, but don't give in.)
- Encourage your child to adjust the volume regularly. Sound levels can vary from song to song, so a safe level on one song can quickly switch to an unsafe level on the next.
- Talk to your children about limiting the amount of time they spend with earphones on. Buy speakers for the MP3 players so they aren't always listening through earphones.
- Have your child's hearing tested regularly and be sure to call the doctor if your child is experiencing ringing in his ears or any other trouble with his hearing. Check out the TweenZone on the Noisy Planet website with your 8- to 12-year old child.
You won't win any parent popularity contests by setting these limits, I know but being unpopular is part of being a good parent. We want our children to be happy and healthy not just now, but in the future. Your children will thank you later when their friends can't hear and they still can!
Back to top
Claire McCarthy, M.D., is an assistant professor in pediatrics at Harvard Medical School, an attending physician at Children's Hospital of Boston, and medical director of the Martha Eliot Health Center, a neighborhood health service of Children's Hospital. She is a senior medical editor for Harvard Health Publications.