Most of the focus with hearing and hearing loss is on the ears and mechanisms within them. In actuality, we really “hear” with our brain! Our brain does the majority of the work in processing what we hear- our ears are the mechanism to get the sounds there.
Hearing and The Brain
Even seemingly “small” environmental sounds – birds chirping, wind blowing, people walking by-our brain processes and uses these sounds to orient us in our environment and keep us aware of our surroundings. When we are processing speech, we are not just processing the words that someone is saying – we are processing rate of speech, intonation and stress – these are all cues that give underlying meaning to what a person is saying. At the same time, our brain is picking up and processing sound from around us and making decisions on what to pay attention to, and what to dismiss. All of this happens in milliseconds, so you can respond correctly not only to the words, but also the emotion of what someone is saying, all while multiple people are talking at the same time! In addition, there is generally no conscious thought required for this process to take place- it’s automatic.
Hearing Loss, the Brain and Memory
However, when hearing loss develops, all of the information that our brains are used to getting diminishes, or disappears completely. Now the brain needs to put more effort into interpreting the information that is coming in, which may be incomplete. Even a mild hearing loss increases the “cognitive load” – the effort the brain uses to interpret speech and sound. Repeated studies on those with mild to moderate hearing loss show they have greater difficulty on tests on auditory memory than those the same age that don’t have hearing loss. The brain is using much more effort to decode (interpret) the signals coming in, rather than using the resources and energy to store it correctly for memory. In short, if you cannot hear correctly, you cannot remember correctly! Those with more pronounced hearing losses will often miss important parts of speech, and struggle to concentrate and follow conversation.
Can Hearing Cause Dementia?
A study from Lin et al (2013) from John Hopkins University showed a significant link between hearing loss and dementia – those with mild to moderate untreated hearing loss were twice as likely to develop dementia. People with more severe hearing loss were three times more likely to develop dementia, even when correcting for other lifestyle factors. Now this does not mean that you are definitely going to develop dementia if you have a hearing loss, but it highlights the importance of our hearing to our cognitive functioning, and that an untreated hearing loss now can have profound consequences later.
As evidence continues to mount that hearing loss is closely linked to memory loss and cognitive impairment, early detection and intervention in hearing loss is key. There is some early evidence that treatment of hearing loss and use of properly fit and adjusted hearing aids can help slow down or prevent some of the cognitive decline associated with losing your hearing.
Our audiologists at Advanced Audiology and Hearing Aid Services can perform complete and in-depth hearing tests to look for hearing loss and to determine the effect it may have on your life. There are many options to treat hearing loss to fit your lifestyle as well – and staying on top of your hearing can help you stay on top of the other things in your life! Visit us at our offices in Danbury, New Milford, Norwalk and Ridgefield in Fairfield County, CT.
– Melissa Tatton Lev, Au.D.