Hearing loss has long been considered a normal and an acceptable part of aging. It is common as estimates suggest that it affects 2 out of 3 adults, age 70 and older. Unfortunately, hearing loss is seldom treated. In the U.S., for example, only 14 percent of adults who have hearing loss wear hearing aids. An important emerging body of research, however, suggests that diminished hearing may be a significant risk factor for Alzheimer’s disease and other forms of dementia — and that the association between hearing loss and cognitive decline potentially begins at very low levels of impairment.