Deafness

Alternative names
Decreased hearing; Hearing loss; Loss of hearing

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

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:

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

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:

     
  • Meniere’s disease  
  • Acoustic neuroma

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

Johns Hopkins patient information

Last revised: December 3, 2012
by Levon Ter-Markosyan, D.M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.