The ear consists of three main parts:
- Outer Ear
- Middle Ear
- Inner Ear
The Outer Ear
The Pinna is the visible portion of the outer ear, where sound waves are collected and channeled into the ear canal to be amplified. These waves then come up against a flexible and oval membrane at the end of the ear canal called the eardrum, which begins to vibrate as the waves hit it.
The Middle Ear
These eardrum vibrations set the ossicles into motion. The ossicles are three tiniest bones in the human body: Malleus (hammer), Incus (anvil) and Stapes (stirrup). They help to further amplify the sound.
The stapes attaches to the oval window that connects the middle ear to the inner ear. The Eustachian tube, which opens into the middle ear, is responsible for equalizing the pressure between the air outside the ear to that within the middle ear.
The Inner Ear
As the sound waves enter the inner ear, they begin to spiral into a snail shaped organ called the cochlea. The cochlea is filled with a fluid that moves in response to the vibrations from the oval window. As the fluid moves, thousands of hair-like nerve endings are then set into motion. These nerve endings transform the vibrations into electrical impulses that then travel along the auditory nerve to the brain.
The brain then interprets these signals and this is how we hear. The inner ear also contains the vestibular organ that is responsible for balance.