The human ear is divided into three parts - the outer, middle, and inner ear. The outer ear collects and directs sound waves through the external auditory meatus to the tympanic membrane. Vibrations from the tympanic membrane are amplified by the ossicles and transmitted through the oval window to the fluid-filled inner ear. Within the inner ear, vibrations stimulate hair cells which transmit signals through the auditory nerve to the brain, where they are perceived as sound. The semicircular canals, utricle, and saccule detect body movement and position for balance and equilibrium.