Most people think of hearing loss as a problem that begins some time later in life, but a new study published Tuesday finds that America’s teenagers are getting harder of hearing as well. About one in five U.S. teens has some degree of hearing loss, according to the study — an increase of about 30 percent over the past couple of decades.
In the study, researchers looked at data from the National Health and Nutrition Examination Survey, a long-running government health study. The researchers looked at two data sets — one collected between 1988 and 1994, and one collected in 2005 and 2006. (NHANES didn’t collect data on adolescent hearing in the years in between.) They found that among a group of about 3,200 teens in the earlier survey, 14.9 percent had at least 15 decibels of hearing loss. By the later survey, 19.5 percent did.
Fifteen decibels is defined as “slight” hearing loss in the study; the percentage of teens with “mild to moderate” hearing loss — at least 25 decibels — increased even more. It jumped from 3.5 to 5.3 percent, an increase of 50 percent.
“So about one out of 20 adolescents has mild to moderate hearing loss,” says researcher Josef Shargorodsky, an otolaryngologist at Brigham and Women’s Hospital in Boston who led the study. “That’s significant, because it means that on average, one kid in every classroom will have evidence of it.”
The researchers also found that boys were more likely than girls to have hearing loss, and that teens living below the poverty level showed more hearing loss than more affluent kids. But the percentage breakout across those demographic categories didn’t change much between the two surveys.
The study, in fact, didn’t pinpoint any specific reasons for the change, although many experts speculate that the increase in portable music players such as iPods, used with headphones, hasn’t helped. Portable music players have been around for decades, but recently they’ve become more powerful and more common, says Tommie Robinson, a professor of pediatrics at George Washington University and president of the American Speech-Language Hearing Association.
“These are very powerful instruments compared to 20 or 30 years ago,” he says. “Also, the other piece is that we’re using them younger and turning them up too loudly.”
Perhaps surprisingly, the new research did not find an association between self-reported noise exposure and hearing loss among the teens in the study, but Shargorodsky says that that could be because teens aren’t very good at estimating their noise exposure — they tend to under report it. He says he’d like to study the reasons and risk factors for the “significant” increase in hearing loss in more depth.
So what does this mean for children who already have some hearing loss?
Shargorodsky says that at the “slight” loss level, some people might notice the problem and others might not. But, he says, some studies have suggested “real, measurable differences” in school performance and language acquisition for children even at that level.
Robinson says that the research should provide an impetus to screen for hearing problems in middle schools and high schools as well as when children are getting ready to go to kindergarten, which is when it often happens now. And, he says, parents should “monitor and model” behavior like wearing ear protection at loud concerts and not turning headphone volume up too high.
“What people need to be cognizant of is that once you lose your hearing you can’t get it back. It’s not coming back,” he says. “And so that’s why we have to think about preventing this from happening.