From the Chicago Tribune By Anne Stein  http://www.chicagotribune.com/lifestyles/health/sc-health-0121-hearing-loss-dementia-20150115-story.html

Hearing loss is so common that it's long been considered a normal part of the aging process and no great cause for alarm. But studies from Johns Hopkins University have found links between hearing loss, cognitive decline and dementia. That means that it may be a greater health threat than imagined and that measures as simple as hearing aids could have a huge influence on healthy brain function.

"Hearing loss shouldn't be considered an inconsequential part of aging," said Dr. Frank Lin, assistant professor at Johns Hopkins and an otologist and epidemiologist who studies the effects of hearing loss on older adults.

In one study involving nearly 2,000 men and women age 75-84, Lin and his colleagues found that over six years, cognitive abilities (including memory and concentration) of those with hearing loss declined 30 to 40 percent faster than in people with normal hearing.

A 2011 study of some 600 older adults found that those with hearing loss at the beginning of the study were more likely to develop dementia than adults with normal hearing. In fact, the more severe the hearing loss, the more likely they were to develop dementia; volunteers with mild, moderate and severe loss were two, three and five times more likely to develop dementia than those with normal hearing.

Another study by Lin and his colleagues found accelerated rates of brain atrophy in people with impaired hearing compared with those who had normal hearing. In addition, they linked hearing loss to "deep episodes of stress, depression or bad mood," an increased risk of hospitalization and an increase in the risk of falls.