The ear consists of three main parts:
- Outer Ear
- Middle Ear
- Inner Ear
The visible portion of the outer ear is called the pinna. It collects sound waves like a bowl and channels them into the ear canal where the sound is amplified. The sound waves then travel toward a flexible, oval membrane at the end of the ear canal called the eardrum. The eardrum then begins to vibrate when these sound waves reach it.
The vibrations from the eardrum set the ossicles into motion. These are three tiny bones which are the smallest in the human body, and are named the malleus (hammer), incus (anvil), and stapes (stirrup).
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.
When sound waves enter the inner ear, they travel 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 nerve endings are then set into motion. These nerve endings transform the vibrations into electrical impulses, which 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.