Hearing loss

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Ear anatomy

Overview

Treatment

Hearing loss

Definition:

Hearing loss is the total or partial inability to hear sound in one or both ears.

See also: Hearing loss of aging

Alternative Names:
Decreased hearing; Deafness; Loss of hearing
Considerations:

Minor decreases in hearing are normal after age 20. Hearing problemsusually come on gradually, and rarely end in complete deafness.

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There are many causes of hearing loss. They can be divided into 2 main categories:

Conductive hearing loss (CHL)occurs because of some mechanical problem in the external or middle ear.The three tiny bones of the ear (ossicles) may fail to conduct sound to the cochlea or the eardrum may fail to vibrate in response to sound. Fluid in the middle ear can cause CHL.
Sensorineural hearing loss (SNHL) results from a dysfunction of the inner ear. It most often occurs when the tiny hair cells (called cillia) that transmit sound through the earare injured.This type of hearing lossis sometimes called "nerve damage," although this is not accurate.

CHLis often reversible -- SNHLis not. People who have both forms of hearing loss are said to have mixed hearing loss.

Screening for hearing loss is now recommended for all newborns. In children, hearing problems may cause speech to develop slowly.

Ear infections are the most common cause of temporary hearing loss in children. Fluid may linger in the ear following an ear infection. Although this fluid can go unnoticed, it can cause significant hearing problems in children. Any fluid that stays longer than 8 - 12 weeks is cause for concern.

Preventing hearing loss is more effective than treating it after "the damage is done."

Common Causes:

Genetic:

Osteogenesis imperfecta
Leopard syndrome (multiple lentigines)
Otosclerosis
Robinson type ectodermal dysplasia
Cockayne syndrome
Bjorn pili torti and deafness syndrome
Multiple synostosis syndrome
Hunter syndrome
Taybi oto-palato-digital syndrome
Hereditary nephritis
Mohr syndrome
Hurler syndrome
Waardenburg syndrome
Kartagener syndrome
Fronto-metaphyseal dysplasia syndrome
Morquio syndrome
Trisomy 13 S
Multiple lentigines syndrome
Treacher Collins syndrome
Stickler syndrome

Congenital:

Rubella syndrome
Congenital atresia of the external auditory canal
Congenital cytomegalovirus
Congenital perilymphatic fistula
Fetal methyl mercury effects
Fetal iodine deficiency effects

Infectious:

Traumatic:

Traumatic perforation of the eardrum
Skull fracture (temporal bone)
Acoustic trauma such as from explosions, fireworks, gunfire, rock concerts, and earphones
Barotrauma (differences in pressure)