Hearing loss from explosions or other extremely loud incidents has long been thought to be irreversible. But new research out of the Stanford University School of Medicine shows that there may be hope to reverse such hearing loss.

Using mice, researchers learned that loud noises don't cause structural damage to the cochlea, a component of the inner ear, as previously thought. Instead, the damage is to hair and nerve cells that translate sound waves. While cochlea damage is irreversible, damage to hair and nerve cells can be lessened.

The Stanford study was primarily funded by the Department of Defense and focused on the impact improvised explosive devices (IEDs) have on hearing. "One blast at the level of an improvised explosive device causes hearing loss that turns somebody's hearing from what they might have at 18 to what they might actually end up having at age 75," says John Oghalai, the study's senior author and an associate professor of otolaryngology. Fireworks and airbags produce similar hearing damage in the general population, he says.

While this offers hope for those with major hearing loss from an accident, the means to reverse the damage isn't quite here yet. "Nerve or hair cell damage cannot be fixed yet. However, this is an active area of research and is likely to be more treatable than severe disruptions of major tissue structures," says Oghalai. "I'm very hopeful that in the next year we will come up with a treatment that potentially you could take soon after being exposed to a blast."