How Do We Hear?
Ever wonder how the human body can perceive sound? How do you process your favorite song from the car radio to the inside of your head?
Music is composed of sound waves, which are actually all around us. Some are loud and others are soft. Some are high pitched and others low pitched. These sound waves travel through the ear canal until they hit the eardrum in the middle ear. This causes the eardrum to vibrate. The eardrum passes the vibrations created by the sound waves through the middle ear bones into the inner ear.
The inner ear, or cochlea, is shaped like a snail, and is filled with liquid that carries the vibrations to thousands of tiny hair cells inside of it. Hair cells are responsible for changing the vibrations into electrical signals, which are then sent to the brain through the hearing nerve. Finally, your brain tells you what you are hearing, whether it’s a nice tune or traffic noise. All this happens in a fraction of a second!
However, this ability of hear isn’t foolproof – very loud sounds can do damage to our hearing. How does this happen? As was mentioned earlier, sound vibrations move tiny hair calls in our inner ear. More specifically, the vibrations move a small patch of stereocilia sticking up out the top of each hair cell. The stereocilia rock back and forth with sound. However, if the sound is too loud the stereocilia can break, which causes the hair cell to die. Once a hair cell dies it can no longer send sound signals to the brain, and unfortunately they don’t grow back. This is a cause of hearing loss. Protect your hearing and avoid loud noise exposure.