A poll conducted for The American Speech-Language-Hearing Association (ASHA) found that 53 percent of high school students said they were concerned about hearing loss, compared with about a third of adults.

In the Zogby International poll, more than half of high school students (51 percent) said they had experienced at least one of the symptoms of hearing loss, compared with 37 percent of adults.

Twenty-eight percent of high school students and 26 percent of adults reported having to turn up the volume on their television or radio; 29 percent of students reported saying "what" or "huh" during normal conversations, as did 21 percent of adults; and 17 percent of students and 12 percent of adults said they had tinnitus, or ringing of the ears.

"While the cause of the symptoms was not identified, the polling shows that people are listening louder and longer, habits made easier than ever by strides in technology, but ones that may also contribute to hearing damage," ASHA President Alex Johnson said.

The poll found that more than half of adults reported using their MP3 players for between one and four hours, or even longer, at a time. Most students said they listened for less than an hour at a time.

Fifty-nine percent of students said they played music at a high volume on their MP3 players, compared with 34 percent of adults.

The user manual accompanying Apple’s iPod includes a warning about listening at high volumes.

Johnson, a professor of audiology at Wayne State University, said the National Institutes of Health estimates that 22 million American adults ages 20 to 69 have suffered hearing damage from loud noise.

ASHA recommends listening to music at lower volumes and for shorter amounts of time.

The group also recommends that users replace the popular earbud-style earphones that are sold with many MP3 players. It says noise-canceling headphones or more traditional headphones that cover the ear block more background noise, allowing users to play their music more softly.

Only 23 percent of students and 19 percent of adults said they have bought aftermarket headphones.

A majority of parents (59 percent) said they were concerned about their children suffering hearing loss from listening to electronic devices with earphones, but less than half said they limit the amount of time their children can use those devices. Eight in 10 said they made their children lower the volume, according to the survey.

More than half of parents said they’ve talked to their children about the problem, and 12 percent said they have given them literature or directed them to Web sites.

Only 10 percent of students said that warnings from parents or friends would be an effective way to teach them about the dangers of hearing loss. Forty-three percent of students and 34 percent of adults said they thought television would be the most effective medium.

Congress lends an ear

Reps. Mike Ferguson, a New Jersey Republican, and Ed Markey, a Democrat of Massachusetts, praised the innovations in MP3 and other music technology, but said they would push for more safety studies.

"Listening to music that annoys parents at incredibly high volumes is a rite of passage for kids of any generation," Ferguson said. "I may be speaking only for myself here, but I think as kids we all remember cranking up our radios, for some of us our 8-track players, and singing along with our favorite songs.

"Cranking up the volume on your car stereo to see if your new speakers can crack your back window, sure that’s a lot of fun, but it also can lead to hearing damage for you, for anyone else who’s in the car and anybody within a few blocks of your car."

Ferguson said parents need to be aware of the risk and make their children turn their music down, or even off.

In January, Markey wrote a letter to the NIH seeking more information on the latest research on the risks from portable music players.

James Battey, director of the NIH’s National Institute on Deafness and Other Communication Disorders, said most of the research on noise-induced hearing loss has looked at occupational exposure.

In a letter dated February 14, Battey said researchers have been looking at the effects of music on hearing loss since Walkman-type radios and cassette players went on the market in the 1980s.

"The amount of research on the effects on NIHL (noise-induced hearing loss) by loud music from portable devices decreased slightly in the late 1990s with a resurgence in the past few years following the introduction of the portable MP3 player," Battey wrote. "All of these devices have maximum sound output levels that range from 115 to 130 decibels (dB), which is comparable to the sound level of a jet engine."

He wrote that more research was needed to determine whether different types of headphones had an effect on hearing loss.

CNN’s Dick Uliano contributed to this report.

Comment by Dr. Sims:

 A study in 1998 revealed an epidemic of noise induced hearing loss affecting our children.  At that time, over 12.5% of children ages 6 to 19 were found to have noise induced hearing loss.  (Niskar, A.S., et. al. (1998, April 8). Prevalence of hearing loss among children 6 to 19 years of age: the Third National Health and Nutrition Examination Survey. JAMA, 279(14): 1071-1075).  This study was performed prior to the now widespread use of devices like the IPOD.  Due to the power and the length of time that children are exposed to potentially toxic levels of sound from this type of device, it is reasonable to fear that a much larger percentage of children have permanent, irreversible damage to their hearing.  For decades we have warned our youth of the dangers of noise exposure, but IPODs and MP3 players are the most significant threat to children’s hearing that we have ever seen.  As we have seen in science before:  wonderful technology sometimes carries inherent dangers if not handled correctly.

IPOD Safety tips:  From the research I have seen the volume should be kept below 60% and it is best to replace the “ear-bud” style headphones with a more circumaural style of headphone that blocks out other sound.  Limit your exposure to under 15 minutes at a time.

For parents:  If you can hear the music your child is listening to from a distance of 3 feet, they may be damaging their hearing.