Hearing loss

Hearing loss

Definition:

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

Alternative Names:

Decreased hearing; Deafness; Loss of hearing

Considerations:

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.

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)

Toxic:

Aminoglycoside antibiotics
Ethacrynic acid - oral
Aspirin
Chloroquine
Quinidine

Age-related:

Age-related hearing loss (presbycusis)

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 decreased the likelihood of work-related hearing loss. (See occupational hearing loss.)

Other:

Temporary hearing loss can be caused by:

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

Home Care:

Wax build-up can frequently be flushed out of the ear (gently) with ear syringes (available in drug stores) and warm water. Wax softeners (like Cerumenex) may be needed if the wax is hard and impacted.

Care should be taken when removing foreign bodies. Unless it is easily accessible, have your health care provider remove the object. Don't use sharp instruments to remove foreign bodies.

A hearing aid can be helpful in coping with hearing loss caused by nerve damage.

Call your health care provider if:

Hearing problems are persistent and unexplained
Hearing problems adversely affect lifestyle
There is an association with other symptoms such as ear pain

What to expect at your health care provider's office:

The medical history will be obtained, and a physical examination performed.

Medical history questions documenting hearing loss in detail may include:

Distribution
- Is the hearing loss in both ears (bilateral)?
- Is it in one ear only (unilateral)?
Quality
- Is the hearing loss mild or severe?
- Is all of the hearing lost (inability to hear any sound)?
- Decreased hearing acuity?
- Decreased ability to understand speech?
- Decreased ability to locate the source of a sound?
Time pattern
- How long has the hearing loss been present?
- Did it occur before age 30?
Other
- What other symptoms are also present?
- Is there tinnitus (ringing or other sounds)?
- Is there ear pain?

The physical examination will include a detailed examination of the ears.

Diagnostic tests that may be performed include:

Audiometry (an electronic hearing test)
Auditory response test
CT scan of the head (if a tumor or fracture is suspected)
X-ray of the head
Tympanometry
Caloric test
MRI of the ear (see MRI of the head)

A hearing aid or cochlear implant may be provided to improve hearing.

Review Date: 1/29/2002
Reviewed By: A.D.A.M. Editorial (1/29/02). Previously reviewed by Ashutosh Kacker, Department of Otolaryngology, New York Presbyterian Hospital, New York, NY. Review provided by VeriMed Healthcare Network (10/31/2001).

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