Dementia is a syndrome, not a disease. Dementia is a group of symptoms that affects mental cognitive tasks such as memory and reasoning. Dementia is an umbrella term that Alzheimer's disease can fall under. It can occur due to a variety of conditions, the most common of which is Alzheimer's disease
https://player.whooshkaa.com/shows/dementiaq
episode 24: Ear System Link to Alzheimers pt1
According to several major studies, older adults with hearing loss are more likely to develop Alzheimers disease and dementia, compared to those with normal hearing.