The Amazing Ear
“How do we hear sounds? Do I have a hearing loss, if so, how does it affect me compared to someone with normal hearing?” are just a few of the many questions individuals ask when they are told they have a hearing loss. The ear structures are a very complex organ of the human body. There are many mechanisms involved, starting with a sound wave entering the air-filled ear canal, vibrating through the eardrum, traveling its way through the fluid of the cochlea and finally, neurons sending a message all the way to the brain to be processed.
When someone has a hearing loss, one or multiple mechanisms are damaged or absent that it causes a reduction in the sound quality and the ability to understand speech. There are several different pathologies that cause a hearing loss and each person is very different in how it affects him or her.
What is a Sound?
Take a second and listen to the sounds you hear around you. What do you hear? A door opening and closing, a couple having an argument about what is for dinner, a baby crying? All of these sounds are produced by vibrations in varies frequencies that move through space in the form of a sound wave. These vibrations move air molecules in a ripple form like a rock is thrown into a puddle.
Now think about the different pitches you are hearing. Sound waves have varies different shapes and sizes depending on the frequency of the source. What happens when you throw two different rocks that vary in size into the puddle? You get two totally different ripples, right? This is what happens with frequencies. Big rocks or low frequencies create large ripples, and small rocks or high frequencies create small ripples. These frequencies can range from 20 to 20,000 hertz. The most important frequencies we use in our everyday use are between 250 and 8000 Hz.
How does the Ear Work?
The ear is made of up three structures, the outer ear, middle ear and the inner ear. Each structure plays an important role how a sound wave is used to gain intelligibility. The ear is responsible for amplifying the present sound, converting from a mechanical wave to electrical impulse, and sending the message up to the brain to process. Interpreting the sound waves only take a few milliseconds to do and we don’t even realize it’s happening.
The Outer Ear
Why do you think it is important we have this odd looking piece of cartilage sticking out...