Sound is collected by the pinna, and then travels through the ear canal. The sound strikes the eardrum and causes it to vibrate. The vibrating eardrum causes the bones (ossicles) to vibrate and mechanically conducts the sound through the middle ear to the inner ear. At this point, sound is converted to an electrical impulse and the movement causes fluid to move over tiny hair cells (or nerve endings) in the inner ear. This electrical impulse travels along the auditory nerve (8th nerve) to the brain. The brain then interprets the sound by many physical attributes of the sound to tell us what the sound is. If it is a speech, the brain will decode it by many different cues, such as pitch, temporal pattern, etc. so that we understand what the talker is speaking about.