Hearing loss

Alternative names:

deafness; decreased hearing; loss of hearing

Definition:

The total or partial inability to hear sound in one or both ears.

Considerations:

Prevention of hearing loss is more effective than the treatment.

Minor decreases in hearing, especially of higher frequencies, are normal after age 20. Some nerve deafness (or loss of hearing) affects 1 out of 5 people by age 55. It usually comes on gradually and 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.

Hearing problems may be the reason some children's speech develops slowly.

There are many causes of hearing loss. They may be grouped in several ways. One way divides causes into 2 categories: conductive loss and nerve loss. Conductive loss occurs when the three tiny bones of the ear (ossicles) fail to conduct sound to the cochlea or when the eardrum fails to vibrate in response to sound because of some mechanical problem such as fluid in the ear or disruption of the ossicles. Nerve loss occurs when the nerve is injured by physical or other means. Conductive loss is often potentially reversible; nerve loss is not.

Common causes:

Genetic:

• osteogenesis imperfecta
• Leopard syndrome (multiple lentigines)
• otosclerosis
• Robinson type ectodermal dysplasia
• Cockayne syndrome
• Bjorn pili torti & 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:

• meningitis
• mumps
• measles
• otitis media
• scarlet fever
• ossicular discontinuity
• adhesive otitis

Occupational:
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 decrease the likelihood of work-related hearing loss. (See occupational hearing loss.)

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)

Toxic:

• aminoglycoside antibiotics
• ethacrynic acid - oral
• aspirin
• chloroquine
• quinidine

Aging:

• age-related hearing loss (presbycusis)

Other:

• Meniere's disease
• acoustic neuroma

TEMPORARY (OR SOMETIMES PERMANENT) HEARING LOSS

• 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

Note: There may be other causes of hearing loss. This list is not all inclusive, and the causes are not presented in order of likelihood. The causes of this symptom can include unlikely diseases and medications. Furthermore, the causes may vary based on age and gender of the affected person, as well as on the specific characteristics of the symptom such as quality, time course, aggravating factors, relieving factors, and associated complaints. Use the Symptom Analysis option to explore the possible explanations for hearing loss, occurring alone or in combination with other problems.