"Consumers need to have good information about the potential health concerns posed by these devices," Markey said in a letter to the National Institute on Deafness and Other Communication Disorders.

Markey said that noise above 85 decibels can cause hearing loss depending on the length of exposure and he cited a recent Washington Post article that said Apple has declined to reveal how loud its iPods can go.

All of Apple's iPod players come with earbuds that fit just inside the outer ear, rather than traditional headphones that go over the ear. Apple's devices include batteries that last for several hours.

An NIH representative was not immediately available for comment.

The question about hearing loss from portable music devices is not new, but the issue has reemerged amid soaring sales of players by Apple and other technology companies.

Apple, which dominates the market for the devices, alone sold 14 million iPods during the Christmas holiday quarter and 42 million since October 2001, when it introduced the device. A company representative was not immediately available to comment.

Sony Corp. and Thomson's RCA also sell music players and Cingular Wireless, the largest U.S. wireless carrier, offers Apple's music software in a cell phone.

"People don't want to give up their portable music devices," Markey said in his letter. "However, they need to know whether they are at risk for premature hearing loss and how to protect themselves."

By Jeremy Pelofsky
http://today.reuters.com/News/CrisesArticle.aspx?storyId=N26173908