Now hear this: They all could be contributing to their own hearing loss if they are blasting music for too long and too often.

Because MP3 players and similar devices have become so wildly popular--and because they can pack a strong, long-lasting audio punch, the American Speech-Language-Hearing Association (ASHA), Rockville , Maryland , cautions consumers to tone things down and be more aware of what can happen when they plug such devices into their ears.

"Louder and longer is definitely not the way to use these products," says Brenda L. Lonsbury Martin, ASHA's chief staff officer for science and research. "Eventually, that [behavior] becomes a recipe for noise-induced hearing loss, which is permanent."

Recently, ASHA commissioned Zogby International to poll the nation about its usage habits with respect to some popular technology that provides audio through ear buds or earphones--devices such as Apple's iPod, other MP3 players, and portable DVD players. (Note: In late March, Apple announced the introduction of volume-limiting software for its iPod. ASHA called the move "a step in the right direction.") The results confirmed the need for caution. More than half of high school students surveyed report at least one symptom of hearing loss. More disturbing is that less than half (49 percent) say they have experienced none of the symptoms, compared to 63 percent of adults who say this. The poll did not identify what is causing the symptoms, though it found usage habits that are potentially detrimental to hearing health.

"Our poll tells us that we should take a close look at the potential impact of some popular technology on hearing health," says ASHA President Alex Johnson .

ASHA advises consumers to lower volume levels, limit listening time, and use earphones that--unlike ear buds that come with products like the iPod--block out unwanted sound that can prompt users to increase volume levels. It also encourages the public to see a certified audiologist if they experience hearing loss symptoms, such as needing to increase the volume on the TV or radio or difficulty hearing normal conversation.

"Overall, we believe that public education is a big part of the solution," Johnson says. "We intend to redouble our efforts with a focus on prevention. Many of our members are school based. Through them and others, we plan to reach out to younger kids--to their parents, significant adults, and educators. This is so important, because even minimal hearing loss can significantly harm the social and educational development of children,"

For more information, visit www.asha.org.

--- Joseph Cerquone is director of public relations, American-Speech-Language-Hearing Association, Rockville , Mary-land.