If you’re like most people in San Francisco with a basic understanding of the hearing process, you probably assume your ears are responsible for hearing. In reality, your brain does most of the work! We’re not saying your ears aren’t important. After all, you need them to keep your sunglasses from falling off.
OK, they serve other important functions, as well. But when it comes to hearing, they actually play a secondary role.
Let’s Hear it for the Brain
To understand how your brain is responsible for hearing, let’s take a look at how auditory processing works. The ear is made up of three parts – the outer, middle and inner ear. Sound waves enter the outer ear and are funneled through the middle ear to the inner ear, where vibrations stimulate tiny hair cells in the cochlea. These hair cells transmit the electrical impulses generated as a result of this movement to the brain via the auditory nerve, where they are translated into sounds we can identify. The brain is able to discriminate relevant sounds from background noise, filtering out unimportant and distracting sounds so we can concentrate on what we are listening to. The brain also amplifies the volume of our own speech, boosting the sounds we make to enable us to hear our own voices clearly.
Think of it this way: the ears are a delivery system, but the brain is the true workhorse, responsible for turning a jumble of noise into coherent messaging.
Hearing Loss, Tinnitus & The Brain
Just as the brain is responsible for hearing, it also must take some of the blame when it comes to auditory processing disorders. The ears may still deliver electrical signals as normal, but the brain can have trouble processing them into recognizable sounds. This often occurs as a result of aging, structural abnormalities or untreated hearing loss that causes auditory deprevation. Changes in auditory processing can make it difficult for patients with hearing loss to understand sounds, even when treating their impairment with amplification (hearing aids).
The brain also plays a role in tinnitus, the perception of noise – usually described as a ringing in the ear(s) – despite the absence of a physical sound source. Tinnitus has many causes, but researchers believe one of the most common may be the result of changes in the brain associated with hearing loss; this causes neurons in the brain to misfire, leading to the perception of sound. Tinnitus retraining therapy, which relies on a series of patterned musical tones, can help retrain the part of the brain responsible for interpreting sound, allowing the neurons to return to their natural state.
Your Walnut Creek audiology clinic can help answer any questions you have about hearing loss, tinnitus and the role your brain plays in auditory processing.