ABOUT SIX MILLION AMERICANS use a hearing aid, but that number should be larger. A Duke University study found only one in five in the U.S. who could benefit from a hearing aid actually has one—and just a third of those with one use it.

“Quality of life can increase dramatically with hearing-aid use,” says Linda K. George, PhD, project director of the study. “There’s the risk to life and limb. On the road, you can’t hear horns, sirens or other warnings. At home, you can’t hear alarms or knocks on the door. You’re always being startled. Not hearing footsteps or greetings puts you on edge. It takes a toll.”

Most damaging of all hearing-loss–related debilitations, though, may be social breakdown. “Conversation is the currency of living,” Dr. George asserts. “If you can’t participate, you’re cutting off a major vehicle for what makes us human. Everyone from your tax attorney to your family, if you can’t understand them or speak with them, you’re eventually going to be cut off from the world.”

Getting and using a device, though, is still only half the battle. “You have to get adjustments due to changes in both your hearing and the device. Like a car, it requires care and maintenance,” Dr. George notes. “So many people try three or four devices that seem to work for only a short while and then toss them and give up, when getting it serviced could improve their hearing, their satisfaction and their lives.”