Hearing loss among teenagers is on the upswing, according to research just published in the “Journal of the American Medical Association.”

“It was a very good study, well defined,” said pediatric otolaryngologist Cecilia Helwig, of Danville.

And its results were surprising.

“We expected to find less,” Helwig said.

That’s because new vaccines protect children from diseases that harm their hearing, and there has been a concerted effort to educate parents and teenagers about noise-induced hearing loss.

Instead, the rise.

“One thing the study could not show,” Helwig said, “is why.”

Suspect is increased listening to music, at higher volumes and frequencies, especially with the use of personal stereo gadgets.

But in the Valley, another risk factor is hunting and shooting.

“It’s not unusual to see unilateral mild hearing loss among avid hunters,” Helwig said. “It increases as you get older and can become permanent or lead to tinnitus (ringing in the ears).”

Of interest to music consumers, she said, is an Australian study that showed hearing loss risk up 70 percent among users of iPods and MP3 players compared with children who don’t use those devices.

And teenagers, when surveyed, usually don’t think their music is too loud, Helwig said. Admittedly, her own teenager did not pay attention to such warnings.  

Perhaps kids will listen to kids.

That’s what the National Organization for Hearing Research Foundation is banking on in adopting Sophie Kaye as its “Spokeschild.”

Seventeen-year-old Kaye, who knows the devastating effects of hearing loss, wants all kids to know noise-induced hearing loss is entirely preventable.

They can turn it down, leave the party, or wear earplugs.

She tells kids that their hearing depends on thousands of microscopic, hair-like sensory receptors that populate the inner ear.

Arrayed like little bundles, they react to sound vibrations and transmit them to the brain where they become “hearing.”

Some vibrations are just too intense for those hairs and cause them to break off. The more breakage, the more hearing loss.

They never grow back.

“Teenagers expose themselves to dangerous noise levels on a very consistent basis,” Kaye said in an interview from her home in New York City.

A cavalier attitude toward such noise, she said, is foolish.

Kaye explained the difficulty of dealing with hearing loss:

You feel like there is a wall of sound insulation surrounding you and you can’t break out.

You can’t hear conversations at normal levels. You have to play the television or radio louder than other people like.

Your friends may begin to avoid you because they tire of repeating things. They think you’re ungracious or obnoxious, so you become isolated.

You miss important information, like instructions in school.

You are less safe, because warnings, like sirens can’t be heard. You can’t hear the oncoming car …

Kaye has struggled with problems like these for more than half her life. She lost virtually all hearing in her left ear, and some in her right, when she was 7. Today, she wears a device that picks up sound on her left side and transmits it to her right ear. Living normally, however, is still a challenge.

“People don’t know how much their hearing matters until it begins to disappear,” Kaye said.

Although the cause of her hearing loss is not known, she is speaking out about noise-related hearing loss because it’s something teens can do something about.

She tells adults it is very important to talk to young children about protecting their hearing because listening habits develop at a very young age.

“Hearing loss is also gradual, so you’re not going to notice it until it’s too late,” she said.

Kaye has a website — sophiesoundcheck.org — and her compelling personal video is featured on the National Institutes of Health website, noisyplanet.NIDCD.NIH.gov

NIDCD is the National Institute on Deafness and other Communication Disorders. It estimates 15 percent – that’s about 26 million — of Americans between 15 and 69 have high frequency hearing loss because of exposure to loud sounds or noise at work or during leisure activities.

Kaye’s advice:

Educate yourself on the simple things you can do to protect your hearing.

“If at a concert, wear ear plugs,” she said.

A lot of people will tell you they get ringing in their ears when they leave a concert, she said. Sometimes it stops and sometimes it doesn’t, she said, but even if it stops, the damage is building up, making the delicate parts of the ear more susceptible the next time.

“At home, listen responsibly,” she advises. “Set the volume as low as you possibly can and still enjoy the music,” she said.

“If you’re at a restaurant where you can’t hear the person sitting close to you without raising your voice, it’s too loud. Ask the waitress if the music can be turned down. If they say it’s not possible, leave.”

Kaye thinks kids trust and believe her.

“I’m young. I’m approachable and I’m interested in helping people,” she said.

Concern about hearing loss in kids increased with the advent of loud rock bands and grew with the use of MP3 players and iPods that deliver the music straight down the ear canal.

The Aug. 18 report in the “Journal of the American Medical Association” compared audiological studies of 2,929 children between 12 and 19 in 1988-94 and of 1,771 children of the same age group in 2005-06. The researchers in Boston concluded that hearing loss increased from 14.9 percent to 19.5 percent in the intervening years.

Fueling the expectation that hearing loss would decline was a decade and a half of education initiatives.

In 1995, for instance, a video featuring the popular band Metallica, “Hearing Health and Loud Music,” aired before 8 million students nationwide.

More studies are required to pinpoint the cause of the increase.

Regardless, “Wear ear protection,” says New York audiologist Craig Kasper.

If you find yourself in a noisy environment, whether it be music or power tools, use ear plugs.

“Even hairdryers,” he said, “are loud enough to pose a long term potential danger.”

Kids will tend to turn up the volume if there is other noise in the room or if it’s a song they like, said Krystal Strazik, audiologist at Central Susquehanna Surgical Specialists in Lewisburg. For about $50, she said, parents can buy a decibel meter. Anything over 85 decibels should be considered in the danger zone. At full volume some listening devices put out 100 decibels.

“I tell them if a person can hear the music outside of the earbuds, it’s too loud,” said Wendy Dwigans, audiologist at Children’s Hospital of Wisconsin.

Dwigans recommends parents get volume-limiting ear phones for their children.

There are a number of these on the market, including Kidzone Earbuds, LoudEnough, Griffin Technology MyPhones and Ultimate Ears. Many are designed for small children.

Satisfaction with these varies. Some have muffled the sound too much, according to online product critiques. One product will probably not suit all.

Strazik said children can find good advice at websites like listentoyourbuds.org and turnittotheleft.com.

Despite these efforts, it is clear that many children tend to listen to their portable music devices with the volume set too loud, says Roland Eavey, director of the pediatric ear, nose and throat service at the Massachusetts Eye and Ear Infirmary.

“Adolescents are not particularly aware of the fact that they are unintentionally doing damage to their hearing,” he said.