Study finds 1 in 5 teens has hearing loss

CHICAGO - Teenagers aren't necessarily tuning out adults; they simply might not be able to hear them.

A stunning one in five teens has lost a little bit of hearing, and the problem has increased substantially in recent years, a new national study has found.

Some experts are urging teenagers to turn down the volume on their digital music players, suggesting loud music through earbuds may be to blame - although hard evidence is lacking. They warn that slight hearing loss can cause problems in school and set the stage for hearing aids in later life.

"Our hope is we can encourage people to be careful," said the study's senior author, Dr. Gary Curhan of Harvard-affiliated Brigham and Women's Hospital in Boston.

The researchers analyzed data on 12 to 19-year-olds from a nationwide health survey. They compared hearing loss in nearly 3,000 kids tested from 1988-94 to nearly 1,800 kids tested over 2005-06.

The prevalence of hearing loss increased from about 15 percent to 19.5 percent.

Most of the hearing loss was "slight," defined as inability to hear at 16 to 24 decibels - or sounds such as a whisper or rustling leaves.

Extrapolating to the nation's teens, that would mean about 6.5 million with at least slight hearing loss.

Those with slight hearing loss "will hear all of the vowel sounds clearly, but might miss some of the consonant sounds" such as t, k, and s, Dr. Curhan said.

While the researchers didn't single out iPods or any other device for blame, they found a significant increase in high-frequency hearing loss, which they said may indicate that noise caused the problems. And they cited a 2010 Australian study that linked use of personal listening devices with a 70 percent increased risk of hearing loss in children.

The findings appear in Wednesday's Journal of the American Medical Association.

Loud music isn't new, of course. Each new generation of teenagers has found a new technology to blast music - from the bulky headphones of the 1960s to the handheld Sony Walkmans of the 1980s.

Today's young people are listening longer, more than twice as long as previous generations, said Brian Fligor, an audiologist at Children's Hospital Boston. The older technologies had limited battery life and limited music storage, he said.

Some young people turn their digital players up to levels that would exceed federal workplace exposure limits, Mr. Fligor said. In Mr. Fligor's own study of about 200 New York college students, more than half listened to music at 85 decibels or louder. That's about as loud as a hair dryer or a vacuum cleaner.