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. It is designed to collect sound waves and channel them into the ear canal where the sound is then amplified. Next, the sound waves travel toward a flexible, oval membrane at the end of the ear canal called the eardrum. The waves cause the eardrum to vibrate.
The Middle Ear
The vibrations from the eardrum set the ossicles into motion. The ossicles are three little bones (the smallest bones in the human body): Malleus (hammer), Incus (anvil) and Stapes (stirrup) that continue to 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, equalizes the pressure between the air outside the ear and that within the middle ear.
The Inner Ear
The sound waves enter the inner ear and move into a snail-shaped and fluid-filled organ called the cochlea. The fluid in the cochlea is moved by the vibrations from the oval window. As the fluid moves, thousands of nerve endings are set into motion. These nerve endings change the vibrations into electrical impulses that move along the auditory nerve to the brain. Once the brain receives these impulses, it interprets them. This interpretation is what we hear. The inner ear is also home to the vestibular organ that is responsible for balance.