There are two general categories of hearing loss. Sensorineural hearing loss occurs when there is damage to the inner ear or the auditory nerve. This type of hearing loss is permanent.

Conductive hearing loss occurs when sound waves cannot reach the inner ear. The cause may be earwax build-up, fluid, or a punctured eardrum. Medical or surgical treatment can usually restore conductive hearing loss.

One form of hearing loss, presbycusis, comes on gradually as a person ages. Presbycusis can occur because of changes in the inner ear, auditory nerve, middle ear, or outer ear. Some of its causes are aging, loud noise, heredity, head injury, infection, illness, certain prescription drugs, and circulation problems such as high blood pressure.

Presbycusis commonly affects people over 50, many of whom are likely to lose some hearing each year. Having presbycusis may make it hard for a person to tolerate loud sounds or to hear what others are saying.

Source: National Institute on Aging, U.S. National Library of Medicine