Both hearing loss and mental decline are common complaints among the elderly. This study found a link between the two. That is that hearing loss could precipitate the mental decline.
While noting the connection, the researchers did not find a definitive reason. They did come up with a couple of theories, like hearing loss created more social isolation or that the brain uses more resources trying to decode unclear sounds and therefore fills up working memory.
They did suggest that this was a good reason to make sure any hearing or vision loss was treated because it could lead to other difficulties.
Can read the original article here:
Hearing Loss Linked to Mental Decline in Elderly
WebMD Health