By Mary Ann Allen, Au.D., CCC-A, of HearingLife Greensboro

     When you think of hearing, chances are you automatically picture your ears. You may be surprised to learn that your brain plays as important of a role as your ears in helping you hear sounds.

Hello: From your ear to your brain

     Imagine that a child is calling to you from the other side of a crowded restaurant: “Our table’s over here!” How do her words reach you? First, the sound waves generated by her words enter your outer ear canal and pass through the eardrum to the inner ear, also known as the cochlea, which is lined with thousands of tiny hair cells. Then, these hair cells turn the vibrations into electrical signals, which are sent to the brain via the auditory nerve.

     As important as the ear’s work is, it’s the brain that makes sense of all those signals. It receives and processes them, determining where they originated, filtering out background noise and amplifying sounds as needed. Finally, your brain sends you a message: That’s a sound you just heard. A child is calling, “Our table’s over here!”

So, what can go wrong with this?

     As we age and as we encounter very loud sounds, the hair cells in the cochlea can become damaged. Instead of standing straight up to receive sound waves, they droop – and die. Once they are dead, they can’t grow back. So, when someone speaks, there are fewer hair cells to send electrical signals to your brain, making it more difficult for your brain to process and recognize words. Usually high-frequency cells suffer damage first – which is why many people with hearing loss have trouble understanding high-pitched sounds such as a child’s voice. Noisy settings exacerbate the problem. So, when that child calls out, “Our table is over here!” in a loud restaurant, your brain may struggle to identify the source of the sound and the words themselves.

     As hair cells die and are no longer able to process and send signals to the brain, people often experience a cascading effect. They have to work harder to hear, which can lead to fatigue and frustration, which can lead to depression and isolation. Some research suggests that the brain undergoes change as well. Frank Lin, MD, PhD, a researcher at Johns Hopkins University, has conducted studies that found an increased risk for dementia in people with hearing loss. He believes that could be due to one or more factors, including the extra stress on your brain to process sound when you don’t hear well, or brain atrophy when the hair cells no longer send as many signals to the brain.

Get help for the brain drain

    Many believe that use of hearing aids can remove some of that stress on the brain. Lin currently is conducting a five-year study on that subject. In the meantime, he advises those with hearing loss to use hearing aids.

As research has focused in on the importance of the brain in hearing, hearing aid manufacturers have worked to develop advanced aids that help the brain do its part of the job more effectively. For example, the Oticon Opn has what the manufacturer calls BrainHearingTM technology, which helps both ears work together more efficiently and aids the brain in separating speech from noise in busy environments.

More information

Take care of your hearing – and your brainpower. If you believe you have hearing loss, give our office a call at 336-272-1721 to schedule a hearing test.

Mary Ann Allen, Au.D., CCC-A, is an audiologist at HearingLife Greensboro. She is a doctor of audiology who also has earned national certification from the American Speech-Language-Hearing Association. A practicing audiologist since 1998, Mary Ann has extensive experience in evaluating hearing loss and fitting patients with hearing aids and other technology to help them maximize their ability to hear.