Hearing with Your Brain - Alzheimer's and Hearing Loss

Our ears may capture sound, but we hear with our brains.

Our ears may capture sound, but we hear with our brains.

Many of us assume we hear entirely with our ears, but that’s not exactly true. It helps to think of it this way: When you hear a favorite song on the radio, the radio itself is not the song – it’s the tool that lets you hear the song. Similarly, your ears are the ‘radio’ for your brain. They are the tool that passes the song – or words spoken by a friend, or the giggles of your grandson – to your brain. Your brain then processes and ‘hears’ the sounds.

If it’s been a while since your last science class, the cerebrum is the part of your brain inside your skull. Its job is to handle the daily tasks of life, you might say. It analyzes information, it makes decisions, it stores information, and it processes what your eyes see, your tongue tastes and your ears hear. The temporal lobes are sections of the cerebrum, and they are responsible for hearing, storing new memories and bringing back ‘old’ memories.

Hearing and Alzheimer's Disease

When you experience hearing difficulty, it’s because there is a loss of information entering the brain. The auditory nerve – the part of your brain that carries sound information – begins to weaken. This forces the area of the brain that processes sensory input, like sound, to work harder to make sense of what it is hearing. Weakness of this shared area of the brain is connected to dementia and Alzheimer’s Disease.

This information was first published in a study by Dr. Frank Lin, a researcher at Johns Hopkins University. This study, titled Hearing Loss and Incident Dementia, has been the foundation for much of our understanding of the links between hearing loss and cognitive decline. We’ve always known that losing your hearing had a serious effect on your ability to communicate, but this discovery makes it quite clear that untreated hearing loss will do much more than just stop you from hearing your loved ones.

Being able to hear and remember information is important to enjoying memories with grandchildren.

Being able to hear and remember information is important to enjoying memories with grandchildren.

Losing your hearing is difficult enough, but this area of the brain is also involved in memory. If your hearing is impaired, the brain area that handles both hearing and memory may have to ‘reshuffle’ resources to do its job. Hearing loss can cause further difficulty when processing information in this area of the brain, which may already be struggling. The part of the brain that deals with memory, recall, and association may be weaker than it should if you aren’t able to hear well.

There’s more to this risk than sensory deprivation from a weakening in the auditory nerve. Many people with hearing loss feel socially isolated, and withdraw into themselves. This often leads to loneliness and depression, which are well-known risk factors for cognitive decline. Feelings of loneliness can increase the risk of dementia by as much as 60%.

Of course, not everyone with hearing loss will suffer from dementia or Alzheimer’s, but a recent study showed that people with hearing loss have a 40% greater chance of cognitive difficulty. This is true even for individuals with only a minor hearing loss.

Living with Hearing Loss

Treating hearing loss – even mild loss – sooner rather than later is vital. Providing support to the auditory nerve can help reduce strain on that part of the brain, which may allow it to dedicate more resources to managing memory. This can have the added effect of reducing stress, headaches from prolonged concentration, and improve overall quality of life.

Did you know age related hearing loss begins at 45? If you’re in your 40s, it’s time to get a hearing exam. Addressing even mild hearing loss now will have positive effects on your life as a whole, but can also help your brain function more efficiently. And, if you’re one of the 29 million Americans with type 2 diabetes, be sure to have your hearing checked now regardless of your age, because individuals with the disease often experience hearing loss sooner than their non-diabetic peers (see article The Link between Diabetes and Hearing Loss).

For more information on the connection between Alzheimer's Disease and Hearing Loss, please read articles from reliable sources like Johns Hopkins University's article "Hearing Loss Linked to Accelerated Brain Tissue Loss". It is very important that you get your information from a reliable medical professional before taking action. Alzheimer's Disease can be a overwhelming problem to deal with, and it is strongly encouraged that you take advantage of a free hearing test to address your hearing loss. 

Last Updated: 12/09/2016

Andrew Lekashman