Adam Chernoff says he listens to his iPod about five hours a day. His mother, Julie Chernoff, didn't think much of it when she found herself constantly having to repeat herself to her son.

"We put it off to fact that he was a teenager and wasn't listening to us," Julie Chernoff said.

But Adam said he soon started struggling in his eighth-grade French class.

"I tried to listen to my teacher, and couldn't hear her," Adam said.

Audiologist David Hill determined that Adam had hearing loss, and suspects his iPod caused it.

"That's the most common type of loss in teenagers. If you crank up to 120 decibels, almost instant exposure can lead to hearing loss," Hill said.

The full volume strength for an iPod is 120 decibels, which is louder than the noise while standing underneath an El track with a train rumbline overhead, Kwan reported.

"It's killing the hair cells in the ear. Once they're dead, they never come back. You're born with all the hearing you're ever gonna have," Hill said.

Experts say that iPods and MP3 players should never be played at full volume. If another individual can hear it from several feet away, it's too loud.

The Apple Corporation, which makes the iPod, says it's responding to the issue. The latest iPods have a downloadable program that limits the volume and locks it in, Kwan reported.

Source: http://www.nbc5.com/health/9152401/detail.html