University of Iowa Hearing Loss In Adults About 20-25 million people in the U.S. have some degree of hearing loss.
Most hearing loss occurs in the adult population.
Only 1 million of these people are under the age of 18 years. Hearing loss may be mild, moderate, severe, or total. It may reflect damage to the outer ear, middle ear, inner ear, or auditory nerve. The outer ear consists of the visible ear and ear canal. The middle ear is an air-filled cavity containing three small bones.