The inner ear is made up of the cochlea and the semicircular canals.

The cochlea is the main sensory organ of hearing. Sound vibrations from the middle ear make the fluid in the inner ear move. The fluid then bends tiny hair cells in the cochlea. When the hair cells move, impulses travel along the cochlear nerve to the brain. These nerve impulses are translated into sound in your brain.

The semicircular canals have special cells that detect motion and changes in position. Tiny calcium "stones" inside your semicircular canals help you keep your balance. When you move a certain way, such as when you stand up or turn your head, these stones move around. This helps your brain know which way your body is positioned.