NY Times: How Hearing and Vision Loss Increase the Risk of Dementia

My dad was having trouble with his hearing aides and didn't use them for several months. When he got some new ones that really worked, his brain was out of the habit of filtering out those routine noises like the traffic outside or the cooler coming on. That really brought to my attention why it is that sensory loss is so associated with loss of brain function, even aside from the social aspects.