Mark Hammel’s hearing was damaged in his 20s by machine gun fire when he served in the Israeli Army. But not until decades later, at 57, did he receive his first hearing aids. “It was very joyful, but also very sad, when I contemplated how much I had missed all those years,” Dr. Hammel, a psychologist in Kingston, N.Y., said in an interview. “I could hear well enough sitting face to face with someone in a quiet room, but in public, with background noise, I knew people were talking, but I had no idea what they were saying. I just stood there nodding my head and smiling.”

Hearing loss is one of the most common conditions affecting adults, and the most common among older adults. An estimated 30 million to 48 million Americans have hearing loss that significantly diminishes the quality of their lives.

In a large survey by the National Council on Aging, two-thirds of older adults with untreated hearing loss explained their reluctance to get a hearing aid with statements like “my hearing is not bad enough” or “I can get along without one,” and one person in five said things like “it would make me feel old” or “I don’t like what others will think about me.” However, those in the survey who had hearing aids were, on average, more socially active and less likely to be depressed, worried, paranoid or insecure, and their family members and friends were even more likely than they were to have noticed these benefits.

In addition, a 2011 study by the Better Hearing Institute, found that untreated hearing loss adversely affected productivity, performance and career success, and was associated with a loss in annual income that could reach $30,000. Those in the study with severe hearing loss were twice as likely to be unemployed as people with normal hearing and nearly twice as likely to be out of work as their peers who used hearing aids.

Content provided by New York Times