"It's not the earbud use that's a problem; it's the absolute volume of the sound that's delivered to the ear," says Martha Mundy, a professor of audiology at UNC.

Mundy adds that it is the combined effect of intensity of sound and time spent listening that put the ear at risk.

The iPod and other portable music players are capable of reaching maximum sound levels of 130 decibels.

A live rock concert can reach sound levels approaching 110 decibels, which can cause damage after only 30 minutes.

And the increasing battery life and storage capacity of portable music players encourage longer listening periods, often at levels that surpass 85 decibels - the threshold at which continued exposure will result in hearing loss.

"We always tell families that if the device is turned up so loud that someone has to shout over it to be heard, it's loud enough to damage hearing on a long-term basis," Mundy says.

Allyson Gaiser, a sophomore international studies and history major, says she listens to her iPod on full volume.

"I feel like it's not that loud when I turn it up, but after I take it out my ears, I can't hear as well," Gaiser says.

Jackson Roush, director of the division of speech and hearing sciences at the University, says that many people use mp3 players in noisy surroundings and that they subsequently crank up the volume of their music without realizing it.

"There's a habituation level - if you walk into a bar off a quiet street, it seems very noisy at first," Roush says. "But after you're there for a while, you adapt."

But Roush says he thinks the iPod earbuds and other ear inserts might pose more of a risk to hearing than regular headphones.

"You could be at a higher volume level with the earbud and insert phones than you realize. And when you're trying to overcome background noise, then there's even greater danger.

"The most important thing is to maintain safe output levels," Roush says.

Debra Weisleder, a clinical instructor of audiology at the University, says tinnitus, or ringing in the ears, is a major indicator of hearing damage following exposure to loud music.

"If you're talking about someone who's listening to music at a high level and they walk away and experience ringing … that's a sign that the music is damaging their hearing and it's way too loud," she says.

Weisleder adds that the best way for music listeners to protect themselves from hearing damage is to check the volume of their music frequently and to keep track of the amount of time spent listening.

As long as listeners keep their music at a medium volume, she says, they should be free from fears of hearing loss.

"The thing is, with noise-induced hearing loss, it's all preventable."

By Desiree Shoe
http://media.www.dailytarheel.com/media/paper885/news/2006/01/19/Features/Waxing.Decibels.Harm.Ears-1477577.shtml