ROBERT SIEGEL, host:
More and more American teenagers are suffering hearing loss. That's according to a new nationwide government survey. As NPR's Patti Neighmond reports, it's not clear why, but there is suspicion that wearing earbuds to listen to music may be to blame.
PATTI NEIGHMOND: To understand the extent of hearing impairment we're talking about, we're going to play you some tones that will give you an idea of the amount of hearing loss these kids experience. First this is a high-frequency tone at a normal listening level.
(Soundbite of tone)
NEIGHMOND: Now we're going to lower the volume a little.
(Soundbite of tone)
NEIGHMOND: And teenagers with healthy hearing can hear that drop in volume, but lots of these kids couldn't. Now we're dropping the volume even more.
(Soundbite of tone)
NEIGHMOND: And this where one in five of the kids tested, aged 12 to 19, had difficulty hearing. Researchers say that over the past 15 years, there's been a 30 percent increase in the number of teenagers suffering hearing loss in this range.
Dr. Gary Curhan of Brigham and Women's Hospital in Boston was one of the researchers who analyzed the government data. He says the hearing loss is slight, but studies show even mild hearing loss affects academic performance.
Dr. GARY CURHAN (Brigham and Women's Hospital): They may be able to hear that somebody's whispering but may not be able to understand it, and there have been some people who study hearing loss who distinguish between whether they actually can hear and understand the sounds and whether it's intelligible versus just detectible.
NEIGHMOND: One of those hearing specialists is Dr. Alison Grimes, who sees patients and does research at the Audiology Clinic at Ronald Reagan UCLA Medical Center. She says we've known for centuries that loud noise damages the ear.
Dr. ALISON GRIMES (Audiology Clinic, Ronald Reagan UCLA Medical Center): We know that musicians are at higher likelihood of having hearing loss, whether it's rock musicians or classical musicians. We know that when we go to a concert and we walk out of a concert three hours later, our ears feel full and stuffy, and our ears ring. Those are signs of temporary or possibly permanent damage to hearing from exposure to loud noise.
NEIGHMOND: The study didn't explore why more teens today are suffering hearing loss, but Grimes says there's a pretty likely culprit.
Dr. GRIMES: Probably exposure to MP3 players to personal listening devices to music would be the suspicion that most of us have.
NEIGHMOND: Grimes says most hearing experts agree if you can hear the music from a teenager's earbuds, it's too loud, and for the teenager, it's likely destroying the tiny hairs in the inner ear that respond to particular pitches and help transmit sound to the brain.
Dr. GRIMES: If pieces of that transmission are missing, then the sound that goes up to the brain is not going to be the clear sound that we need to be able to hear to understand speech.
NEIGHMOND: Grimes says research shows the louder the noise and the longer you're hearing it, the greater the risk of hearing loss, and that's why there are standards for noise on the job, and when the noise gets to a certain level, workers are required to wear ear protection and have annual hearing checkups.
But for loud music plugged into the ear, the research isn't clear yet. However, Grimes says there are recommendations.
Dr. GRIMES: Lower volume is safer, and if a person is going to listen at a higher volume, it's a good idea to take to turn it off and take out the earphones for, say, 10 or 15 minutes every hour, give your ears a rest.
NEIGHMOND: For more specific guidance, Grimes suggests going to the American Academy of Audiology website, turntotheleft.org.
Patti Neighmond, NPR News.
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