The ear is the organ that collects and concentrates sound waves. It then converts these waves into electrical impulses so that the brain can process them.
There are three different sections in the ear: the outer ear, the middle ear, and the inner ear. These parts work together to process sounds. The cochlea, in the inner ear, is the hearing part of ear.
The acoustic nerve carries impulses from the cochlea to a relay station in the mid-brain, the cochlear nucleus, and on to other brain pathways that end in the auditory cortex of the brain. 
Ears also help to keep balance (equilibrium); the inner ear contains the sensory organs for balance.