You can see in the diagram that the external ear captures the traveling sound waves. The sound waves enter through the pinna into the ear canal. Through the ear canal the sound waves reach the eardrum. These sound waves cause vibrations of the eardrum that are passed on to the middle ear. The three tiny bones in the middle ear pass the vibrations over to the inner ear. The stapes deliver the sound waves to the cochlea through the round window of the outer part of the inner ear, called the bony labyrinth. These vibrations cause the perilymph fluid present in the cochlea to vibrate. These vibrations are picked up by the sensory hair cells, that translate it into nerve impulses and deliver it to the auditory nerve present at the base of cochlea. The VIII cranial nerve carries the messages to the brain, where it is read and translated into meaningful sounds.
