How We Hear

Our ears are made up of three different parts: outer ear, middle ear, and inner ear. 

Outer Ear

The outer ear consists of the pinna and the ear canal. The pinna and ear canal are responsible for funneling sound into the rest of the ear. 

Middle Ear

The middle ear consists of the eardrum and a chain of three tiny bones: malleus, incus, and stapes. The stapes is the smallest bone in the whole body! When sound waves travel into the ear canal, it causes the eardrum to vibrate, which causes the chain of bones to vibrate too. These vibrations push the sound into the inner ear. 

Inner Ear

The inner ear consists of a snail-shell-shaped organ called the cochlea. The cochlea is filled with fluid. When the middle ear bones vibrate, the fluid in the cochlea moves. The fluid movement excites thousands of tiny hair cells in the cochlea. These hair cells send electrical signals to the brain via the auditory nerve. The brain can interpret these signals as sound.