A new study has shown that hearing loss has a direct effect on cognition.
Researchers at Johns Hopkins found that older people who were hearing impaired were more likely to suffer memory and cognitive problems.
To test the theory, researchers looked at nearly 2000 elderly people between the ages of 75 and 84, said MedPage Today.
When the study commenced all the participants had normal hearing and brain function.
Two tests were repeated three times over the course of the years to mark the declines.
One asked questions about the year, date and time and the other was a matching game.
Researchers found that cognitive problems developed faster if hearing loss began to decline.
USA Today reported that a hearing loss drop to 25 decibels - a mild loss - would see cognitive decline speed up 30 to 40 percent faster.
It is not clear why this happens but the researchers offered two possibilities.
The first is that people who lose their hearing withdraw socially and thus no longer stimulate their brains with conversation.
The other possibility is that the brain is working on overload just to be able to hear.
"If you can't hear the person across from you at the dinner table, you won't be engaged in the conversation," Lin said, according to HealthDay.
"If you're redirecting brain resources to help with hearing," Lin added, "that probably comes at the expense of something else -- like working memory."
The findings were published in JAMA Internal Medicine.