Hearing loss, also known as hearing impairment, is a partial or total inability to hear. A deaf person has little to no hearing. Hearing loss may occur in one or both ears. Deafness is usually the result of inner ear or nerve damage. It may be caused by a congenital defect, injury, disease, certain medication, exposure to loud noise or age-related wear and tear.The chief symptom is an inability to hear sound.For some, hearing may be possible with surgery or a hearing device. Lip-reading skills, written or printed text and sign language may help with communication. There are three types of hearing loss — sensorineural hearing loss, conductive hearing loss, and mixed hearing loss.