We already saw how our ears collect sounds from outside and conduct it to the inner parts. The sound waves are at first collected by the outer ear and passed through the ear canal. It then causes the eardrum to vibrate. Subsequently, these vibrations are transmitted to the cochlea by the tiny bones of the middle ear.
Cochlea is a snail-shaped structure filled with fluid situated in the inner ear. An elastic partition runs from the beginning to the end of the cochlea, splitting it into an upper and lower part. This partition is called the basilar membrane because it serves as the base, or ground floor, on which key hearing structures sit.
Once the vibrations cause the fluid inside the cochlea to ripple, a travelling wave forms along the basilar membrane. Hair cells sitting on top of the basilar membrane ride the wave. The movement of hair cells eventually results in the formation of electrical signals.
The auditory nerve carries this electrical signal to the brain, which turns it into a sound that we understand.