August 17, 2010 -- Brooklyn Miller is a 13-year-old who has a lot in common with other girls her age. She enjoys socializing with her friends and likes to dance.
She also wears hearing aids because of a mild to moderate hearing loss her mother says was caused by chronic ear infections when she was an infant.
That hearing loss is something she has in common with an increasing number of children her age across the country.
Researchers used data from a national heath and nutrition survey done between 1988 and 1994. They compared the number of children ages 12 to 19 with hearing loss in those years to the number of children with a hearing loss in 2005 and 2006. They found that in 2005 and 2006, 1 in 5 children had hearing problems. That represents more than a 30 percent increase since the first survey.
The most common kind of loss was high-frequency hearing loss, though researchers did not determine the reasons why these children lost their hearing.
"This study has put in data what we've suspected all along," said Tommie L. Robinson, president of the American Speech-Language-Hearing Association.
While they don't know for sure, hearing experts have a theory about why more and more teenagers are suffering from hearing loss.
"The high-frequency hearing loss is most consistent with noise exposure," said Dr. John W. House, president of the House Ear Institute in Los Angeles. "I think we're seeing that trend now because of iPods and other personal listening devices that teenagers listen to at high volumes for long periods of time."
Brooklyn Miller didn't suffer from the effects of loud music. But her mother, Susan Miller, worries that her three other children will damage their hearing because of their iPods.
"I keep telling them to turn down their earphones because they're going to suffer from a hearing loss," said Susan. "But they don't relate it to the headphones. To them, it's because Brooklyn has a problem."
Teen Hearing Loss Rises 30 Percent in Survey
That's a message hearing experts want to get out to teenagers and anyone else who uses personal listening devices or is regularly exposed to loud noise.
"We need to change some behavioral things that we're seeing," said Robinson. "We've got to get people to do three things -- turn down the volume, take listening breaks and use ear protection when they're in an environment wth loud noises for extended periods of time, such as concerts or doing yard work."
"Listening devices are fine as long as the volume is at a reasonable level, and they're not listening to them for extended periods of time," said House.
House said the volume of music players can sometimes exceed 110 decibels. According to standards set by the Occupational Safety and Health Administration, exposure to noise levels of 110 decibels for more than 30 minutes requires noise protection in workplaces.
A good guideline, experts say, is to figure out whether the person next to you can hear your music.
"If someone is standing next to you and they can hear your music, it's too loud," said Robinson.
As Brooklyn Miller knows, a hearing loss can make life very difficult. Before her loss was diagnosed, she had trouble in school, and one teacher thought she had attention-deficit hyperactivity disorder. At one point her school suggested she had a low IQ.
"She went through a lot of educational testing," Susan said. "She was a bright kid, but she was struggling somewhere, but we didn't know where."
Last year, she got hearing aids, and they've made a tremendous difference in her life.
"She can finally hear noises, like traffic, that we take for granted," said Susan.
That's why experts say they really want to get teenagers to protect their ears. Their hearing is getting progressively worse.
"Once you lose your hearing, you cannot get it back. It's gone for good," said Robinson.