When your car breaks down, it’s usually time to pop the hood and find that fault. With a complex piece of machinery, a fault can happen in any number of places. That goes both for your car and for your ears. Understanding how hearing loss works first means understanding how hearing works. So, let’s take a look under the hood.
The mechanics of hearing
Your ears are made of 3 parts: the inner ear, middle ear, and outer ear. Sound travels from the outside world into the outer ear first, then the middle ear and finally the inner ear, before your brain steps in to interpret those sounds.
The outer ear acts as a funnel, collecting sounds and channeling them deeper into your ear. It includes your ear canal, which amplifies the sounds before they reach the middle ear.
The gateway to the middle ear is the eardrum, a thin covering that vibrates when sounds reach it. These vibrations pass onto the next part of the middle ear, 3 tiny bones which amplify the vibrations before they pass onto the inner ear.
The inner ear contains a system of tubes that are twisted into a spiral shape, looking a bit like a snail’s shell. These tubes are filled with fluid and contain thousands of tiny cells called hair cells. The tops of these cells look like they’ve sprouted hairs. When vibrations enter the fluid-filled tubes of the inner ear, these ‘hairs’ move. And this is where the magic happens, like when your car hums to life when you turn the ignition.
This is when noise from the outside world becomes sounds that we can understand. When the hair cells move they send signals along a nerve to your brain, which interprets these signals as speech, melodies, the ring of your phone, the clink of the toaster, essentially anything and everything you hear.
As you can see it’s a long and winding journey for sounds to reach your brain. Hearing loss happens when something goes wrong along this journey, which is what we’ll explore next.
What happens when hearing breaks down?
There are different kinds of hearing loss depending on where the fault in your hearing lies. Hearing loss caused by problems with the middle or outer ear is called conductive hearing loss. This is when sound can’t get through into the inner ear. Causes of conductive hearing loss include earwax blocking the ear canal or diseases affecting the tiny bones of the middle ear.
Far more common than conductive hearing loss is sensorineural hearing loss. This is when there is something wrong with the inner ear or the nerve that connects the inner ear to the brain. Causes of sensorineural hearing loss include damage or loss of the hair cells in the inner ear and trouble sending signals down the nerve to the brain.
There was a time when nothing could be done to treat sensorineural hearing loss but then hearing aids were invented. And they kept on getting better and better. Forget flash cars, hearing aids today come packed with a whole lot of advanced technology; Bluetooth, directional microphones, digital signal processing, and the list goes on.
If you’re worried that you may have hearing loss, come see us at Johnson Audiology. We’ll check your hearing health and if you need hearing aids, we can provide you with the latest devices on the market.
Dr. Megan Johnson is the owner and licensed audiologist at Johnson Audiology. She earned a bachelor’s degree in communication disorders from Western Carolina University, a master’s degree in audiology from the University of Tennessee, and her doctorate in audiology from the University of Florida.