The purpose of this test is to measure the speed of conduction of nerve impulses along the hearing nerve. This is done in order to detect masses, scarring, or swelling along the hearing, balance, or facial nerves. The test is performed by a computer which delivers a series of clicks to the patient’s ear via an earphone. The electrodes that are placed on the scalp pick up the brainwaves that are generated by the nerve impulse as it travels from the inner ear to the brain. The computer generates a graph of the brain waves and also calculates the conduction velocity along the hearing nerve pathway.