Hearing loss is a large and growing problem in the U.S. And research suggests that it's not only older adults who are having difficulty, but younger people as well.   

A study published in the journal JAMA Otolaryngology—Head & Neck Surgery this week suggests that the number of American adults with hearing loss is expected to nearly double to 73.5 million in the next 40 year.

But just as worrisome is that early hearing deficits in adolescents and young adults may be more common than previously thought—potentially putting them on the path to serious hearing loss down the road.

And some experts are putting the blame on noise at sporting events and rock concerts, and to headphones and earbuds that blast music into young ears.

On this World Hearing Day, here's what you need to know about how loud listening may be harming teens and how to protect their ears—and yours.  

Whose Hearing is Affected?

Nearly 40 million U.S. adults between 20 and 69 have difficulty hearing some sounds due to noise damage, according to the Centers for Disease Control (CDC).

It's less clear how many younger people are affected. The most recent numbers--from 2005-2006--suggest that roughly 20 percent of Americans between age 12 and 19 experienced hearing problems.

That's five percent more than it was just 20 years earlier.

And recent research suggests that we may be seeing more young people with tinnitus—a ringing in the ears that may be an early sign of hearing damage.

In a study of Brazilian teens and preteens, published in Scientific Reports in 2016, more than half said they'd experienced tinnitus within the prior year.

For most of those surveyed, the bothersome ringing subsided in less than a day. But when researchers followed up with some of the teens a year later, 8 out of 54 still had tinnitus.

Persistent tinnitus is a likely signal of permanent hearing damage, says Larry E. Roberts Ph.D., professor emeritus in the department of psychology, neuroscience, and behavior at McMaster University in Canada, and one of the study's authors.

In addition, "once you have experienced tinnitus, it can reappear, sometimes years later—and then not go away," says Roberts.     

How Noise Can Harm Hearing

It’s long been known that exposure to loud noises can damage tiny hair cells in the ear that receive sound.

When too many of these hair cells are lost, your ability to hear is permanently diminished. "Loud noise is traumatic and can injure inner ear hair cells," says Orly Avitzur, M.D., Consumer Reports' medical director. "And repeated injury is cumulative, just like a blow to the head can injure brains, and repeated concussion can cause serious problems."

Some research now suggests that nerve cells in the inner ear—which relay sounds from the hair cells to the brain—may be especially vulnerable to noise damage.

These nerve cells turn sound into something meaningful—helping “you go from hearing something to understanding it,” explains Stéphane Maison, Ph.D., an assistant professor of otolaryngology at Harvard University.

Damage to nerve cells may make it harder for people to distinguish speech from background noise. This can cause difficulty following conversation in a noisy restaurant, for example.

Listening Too Loud

According to James C. Denneny III, M.D., CEO of the American Academy of Otolaryngology—Head and Neck Surgery,  it has become common for people to listen to music through headphones and earbuds at around 100 decibels (dB). Rock concerts may hit 120 dB.

Frequent exposure to sounds over 85 decibels (dB) over time can impair your hearing, he explains. The louder the sound, the less time it takes.

Just 14 minutes of exposure to sound at 100 dB can begin to damage sensitive structures in the inner ear.

And teens and young adults may be especially likely to expose themselves to earsplitting noise. According to a 2016 report from the World Health Organization (WHO), 1.1 billion young people worldwide face an increased likelihood of hearing loss from risky listening practices.

Nearly 50 percent of people between 12 and 35 listen to unsafe levels of sound on personal audio devices such as smartphones and MP3 players, says WHO.

Protect Those Ears

Take steps to curtail habits that may harm your hearing (or that of teens and younger children) over time. Our experts advise the following:

  • Be especially careful about exposing yourself to loud environments if you've already had tinnitus.
  • Wear earplugs at loud events. Inexpensive foam drugstore products will do. Or, wear earmuffs.
  • Keep the volume on headphones and earbuds at 60 percent or less of maximum volume. Researchers at the Boston Children's Hospital recently determined that listening to music on headphones or earbuds at this volume for an hour a day should be relatively safe.
  • If you're unsure what a safe volume is, Denneny says you should still be able to hear outside conversation when listening. “If the person next to you can hear what you’re listening to on your earphones, that’s over 100 dB and that’s too loud,” he says.
  • Opt for over-the-ear headphones instead of earbuds; this may help safeguard your ears.
  • Consider buying a portable decibel meter from an electronics store, or downloading a decibel meter app on your cell phone. This can give you an idea when you might need earplugs.
  • If you (or your youngster) experience tinnitus or suspect hearing loss, talk to your doctor. He or she can help determine whether a medical issue such as impacted earwax is getting in the way of proper hearing or whether a true hearing problem is the cause.