The Relationship Between Hearing Loss and Cognition

09/21/18

I have a question for you. How many of your patients would you estimate know that the brain translates impulses from the ear into sounds we know and understand? Or that it also discriminates relevant sounds from background noise and turns up our own speech? I would guess not very many. Frankly, I didn’t know until I started working in the industry.

Moreover, how many patients do you think are aware that hearing loss can negatively impact their cognitive health, potentially increasing their risk of developing dementia or Alzheimer’s? With so many recent studies linking hearing loss to cognitive decline, aging adults must realize that hearing loss is more serious than a nuisance that comes with getting older.

Why gray matter matters

Research conducted by the University of Pennsylvania and Washington University in St. Louis revealed that older adults whom had been diagnosed with mild-to-moderate hearing loss scored lower on cognitive tests than those without hearing issues. Another study uncovered that adults with hearing deficiencies also exhibited less gray matter within their auditory cortex, which is vital to speech comprehension.

With the reduction of sensory stimulation from hearing loss, the corresponding areas of the brain are forced to reorganize their functions. Sections that normally control other senses, including touch and vision, invade areas used for processing sound. As a result, a person with untreated hearing loss expends much more energy to understand what they hear. In turn, they are forcing their brain to forego the task of storing what they hear into their memory. And that’s what can bring on short- and long-term memory loss.

They may be listening, but are they understanding what they hear?

The answer is no. A Brandeis University study proved that ignored, untreated hearing loss interferes with a person’s ability to make sense of what they are hearing. Additionally, Johns Hopkins University concluded that senior citizens with mild hearing loss are more at risk of developing dementia in comparison to those with healthy hearing. The researchers also found that loss of brain tissue occurs at a faster rate for those with hearing problems.

When they can’t hear they shy away from personal interaction

Anyone who has mild-to-moderate hearing loss and does not seek help may be accelerating loss of brain function. Knowing they will have difficulties carrying on one-on-one conversations, especially when out with a group in a noisy environment, people hard of hearing tend to isolate themselves. Not only does this affect personal relationships, but it also creates a void in brain function. When you don’t interact with others, gray matter in the auditory cortex remains unworked. As a result, that area of the brain shuts down, which can adversely affect the cognitive process and lead to dementia.

What can an audiologist do to help prevent cognitive issues?

Be proactive. Keep spreading the word out about the importance of annual hearing checks for middle-aged adults and senior citizens. Likewise, keep informing patients of the positive impact of hearing aids. The National Institute on Deafness and Other Communication Disorders (NIDCD) notes that only 25 percent of people who need hearing aids have them. People need to know that the earlier hearing loss is detected and treated, the less chance there is for them to develop cognitive issues.

Reinforce the fact that social stigmas and embarrassment are a thing of the past. Point out how Whoopi Goldberg, Bill Clinton, and Jodie Foster are among famous people who proudly wear hearing aids. Show them newer models of hearing aids that are basically invisible, and inform them of the cool things they can do, such as connect to smart technologies. Demonstrate how hearing aids provide the stimulation the brain must have so it can react to and process sounds that had been previously unheard.

Simply put, hearing loss is part of the natural process of getting older. However, the prevention of hearing loss and impairment by wearing hearing aids could delay or even substantially reduce the onset of cognitive decline. And that is the most important message you can tell anyone who comes to you for help.