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

Minor decreases in hearing are normal after age 20. Some deafness related to nerve damage affects 1 out of 5 people by age 55. It usually comes on gradually, and it rarely ends in complete deafness. See hearing loss of aging. Alzheimer's disease or other neurological problems may sometimes be falsely suspected in older people because they have hearing problems.

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

• Conductive loss occurs because of some mechanical problem, such as fluid in the 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.
• Nerve loss occurs when the nerve is injured by physical or other means.

Conductive loss is often reversible -- nerve loss is not.

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 can 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 lasts longer than 8-12 weeks is cause for concern.

• 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

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

• Meningitis
• Mumps
• Measles
• Ear infection (otitis media)
• Scarlet fever

• 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)

• Aminoglycoside antibiotics
• Ethacrynic acid - oral
• Aspirin
• Chloroquine
• Quinidine

• Age-related hearing loss (presbycusis)

• Any occupation with chronic exposure to loud noises on a continuous day-to-day basis can result in hearing loss due to nerve end damage. Increased attention to conditions in the work environment has markedly decreased the likelihood of work-related hearing loss. (See occupational hearing loss.)

Other:

• Meniere's disease
• Acoustic neuroma

• The build-up of wax in the ear canal(s)
• Foreign body lodged in the ear canal
• Injury to the head
• Allergy
• Blocked Eustachian tubes
• Scarred or perforated eardrum
• Ear infections (otitis externa - chronic, otitis media - chronic, otitis externa; malignant)
• Reaction to medication such as aminoglycosides, chloroquine, quinidine