About 1 in 5 Americans have troubles with hearing loss

According to a new study more than 48 million people in the United States over age 12 have trouble hearing in one or both ears, and the way we listen to music is partly to blame.

“Sometimes aging and genetics play a role, but what today we know that environmental exposures - like listening to music too loudly - can promote to long term hearing damage over time,” says Dr. Frank R. Lin, lead study author and assistant professor of otolaryngology-head and neck surgery and epidemiology at Johns Hopkins School of Medicine. “It’s a growing concern.”

How headphones cause hearing loss: You have your headphones on and are jamming to your favorite music on maximum volume. The sound waves enter the ear, travel through the ear canal all the way to the hair cells located in your inner ear. Hair cells help convert sound energy into electrical signals sent to the brain. And this allows you to hear the music clearly. But when the volume is too loud, those hair cells get damaged and never grow back.

“We should know that the impact of loud noise exposure won’t be seen for many years later,” says Lin. “So we aren’t aware we are damaging our hearing until it’s too late.”

Hearing loss happens gradually. And people's susceptibility to permanent hearing loss depends on several factors including their own genetics, the background noise they are exposed to and how loud they are listening to music, according to Lin.

So how noise can be too loud?

Experts don’t have an exact calculation as to how loud, for how long, is too much. But researchers do know that the louder the noise, the less time it takes to cause damage to your hearing.

Remember this number: 115 decibels (dB). That’s how loud the average MP3 player is playing music at maximum volume. According to the American Academy of Otolaryngology, listening to an MP3 player at 100db for just 15 minutes can cause hearing loss. Also, music at 85dB for prolonged, repeated times can cause damage.

“It is important to know that once the hair cells in your ear have been damaged, your body can’t replace them. It’s permanent hearing damage,” says Lin, whose research is the first comprehensive national estimate of hearing loss in the United States.

So if you want to try to keep from joining the one in five Americans with hearing loss, turn the volume down a notch and choose headphones that rest on the ear, versus ear buds that sit in the entrance of the ear canal. And a good rule of thumb for parents: If you can hear your kid's music through their headphones, it’s probably too loud.