The inner ear includes the cochlea, the cochlear nerve, and the semicircular canals.

The cochlea is the main sensory organ of hearing. Sound vibrations from the eardrum in 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 changed into sound in your brain.

The semicircular canals help you keep your balance. They have special cells that detect motion and changes in position. When you move a certain way, such as when you stand up or turn your head, the special cells sense the movement. This helps your brain know what position your body is in.