Hearing loss has generally been viewed as an inevitable part of the aging process. But, a new study in the Archives of Internal Medicine finds that more than 48 million Americans over the age of 12 have trouble hearing in one or both ears and loud music could be partially to blame.

"It is definitely a growing problem," said Dr. Jennifer Elfert, an Audiologist in Central Jersey. "When you see a child that's 12 or 15 years old suffering from hearing loss, you know they are generally not in the military shooting guns or skeet shooting, so you can figure that the only logical cause of hearing loss is either a head trauma or loud music over time."

"Inside the inner ear, there are nerve endings called hair cells and each one corresponds to certain frequencies," said Elfert. "There are certain nerve endings that are more effected by noise exposure and over exposure forms notches in that section of the inner ear."

Hearing loss is gradual and susceptibility to permanent hearing loss depends on several factors including genetics, background noise and how loud one is listening to music. How do you know how loud is too loud?

"Basically, if you walk by your child and you can hear their headphones, chances are, the music is too loud," said Elfert. "Once those hair cells have been damaged, your body doesn't replace them."

That's not to say that you can never listen to loud music. "It's continued exposure at that volume and depending on how loud it is as little as 12 minutes at a high volume can cause a temporary shift in hearing," said Elfert.