Researchers at Columbia University Vagelos College of Physicians and Surgeons in New York have found that even the earliest stage of hearing loss—when hearing is still considered normal—is linked to cognitive decline, according to a study published in JAMA Otolaryngology–Head and Neck Surgery.
“Physicians in this field have used 25 dB—about the loudness of a whisper—to define the border between normal hearing and mild hearing loss in adults, but this level is arbitrary,” said Justin S. Golub, MD, MS, assistant professor of otolaryngology–head and neck surgery at Columbia University Vagelos College of Physicians and Surgeons and a hearing specialist at Columbia University Irving Medical Center and New York Presbyterian Hospital. “It has been assumed that cognitive impairment wouldn’t begin until people passed this threshold. But no one actually looked at whether this was true.”
The researchers looked at data from 6,451 adults (with an average age of 59) who were enrolled in two ethnically diverse epidemiologic studies. Participants underwent hearing and cognitive testing as part of the studies.
Dr. Golub and his colleagues found that for every 10 dB decrease in hearing, there was a significant decrease in cognitive ability, a pattern seen across the entire spectrum of hearing. Further, the largest decrease in cognitive ability occurred in those whose hearing was just starting to become impaired, just 10 dB off the perfect mark.
“Most people with hearing loss believe they can go about their lives just fine without treatment, and maybe some can,” said Dr. Golub. “But hearing loss is not benign. It has been linked to social isolation, depression, cognitive decline, and dementia. Hearing loss should be treated. This study suggests the earlier, the better.”