The Truth Behind Hearing Loss, Hearing Aids and Dementia

There has been a lot of talk lately on the links between untreated hearing loss and cognitive health. Do hearing aids help prevent dementia if you have hearing loss? Does hearing loss mean I’ll get dementia? How are dementia and hearing loss even related? This article aims to clarify these questions and explains the relations between our ears and the brain.

How are hearing loss and dementia related?

The brain and the ears have a close relationship. Hearing involves an extremely complex mechanism which involves our ears changing sound in the form of sound pressure waves into electrical signals which our brain processes as sound. Our ears help stimulate the brains auditory cortex so we can make sense of the world around us. If we are born using speech as our primary form of communication, our ears help us socialize and engage with the world around us. A decrease in hearing also means a decrease in brain stimulation in the auditory cortex.

Much like a muscle which will shrink if you stop exercising, the auditory cortex shrinks faster (by about 1 cubic cm per year 1) if it is not being stimulated by the ears. Some studies have shown additional recruitment from the frontal lobe which is could possibly be maladaptive, as the main function of the frontal lobe is for higher cognitive functioning, like problem solving and executive function 4. Generally speaking, a decrease of stimulation in the auditory cortex from the periphery (your ears due to hearing loss) causes the brain to shrink faster than it normally would, and causes a reallocation of resources as a result, which could cause cognitive disease over time.

Studies show an association between untreated hearing loss and cognitive disease, with even just a mild loss doubling your risk factor 1,2.

How do I minimize the risk between hearing loss and cognitive health?

First and foremost, protect your hearing! Be sure to turn down your headphones, or even better, turn on the safety limiter to ensure your headphones never get too loud. Protect your hearing in loud spaces like a sporting event or a concert. As a rule of thumb, if you’re yelling to speak to the person across from you, the space you’re in is too loud! Hearing protection is recommended in these spaces. If you need to hear people but would like to it safely, custom hearing protection has filtering technology that can allow you to do that! Do you love music but hate the way it sounds through ear plugs? Try musicians plugs which have a filter, ensuring great sound quality and safe hearing.

Do hearing aids help if I have hearing loss?

Research seems to point towards yes! A large study spearheaded by Dr. Frank Lin compared the cognition of adults who had hearing loss and treated it, and those who did not. In this study, there was a subpopulation of adults who had other comorbidities that might increase their risk of cognitive disease.

In adults that had a greater risk of cognitive disease, hearing aids seem to reduce the accelerated risk by almost 50% over a three-year time span. While no major changes were seen in healthy adults, researchers believe this is likely because healthy adults would not exhibit major changes to their cognition over a three-year time span the way higher risk adults would, and therefore a longer-term study might help us understand the impact of hearing aids and cognition on healthy adults 3.

I have a hearing loss, does this mean I’m doomed?

Absolutely not. Risk does not mean cause. While treating hearing is advised as it is an easily reversible risk factor, having hearing loss does not mean you will get a cognitive disease.

I hope this article clarifies some questions you might have had when it comes to hearing loss and cognition. If you have more questions on the topic and you are in Toronto or the Forest Hill area, please don’t hesitate to stop by the clinic, we would love to meet you!