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Hearing loss

Definition

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

See also:

• Hearing loss - infants
• Hearing loss of aging
• Sensorineural deafness

Alternative Names

Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss

Considerations

Minor decreases in hearing are common after age 20.

Hearing problems usually come on gradually, and rarely end in complete deafness.

There are many causes of hearing loss. Hearing loss can be divided into two main categories:

• Conductive hearing loss (CHL) occurs because of a mechanical problem in the outer or middle ear. The three tiny bones of the ear (ossicles) may not conduct sound properly, or the eardrum may not vibrate in response to sound. Fluid in the middle ear can cause this type of hearing loss.
• Sensorineural hearing loss (SNHL) results when there is a problem with the inner ear. It most often occurs when the tiny hair cells (nerve endings) that transmit sound through the ear are injured, diseased, do not function properly, or have prematurely died. This type of hearing loss is sometimes called "nerve damage," although this is not accurate.

CHL is often reversible. SNHL is not. People who have both forms of hearing loss are said to have mixed hearing loss.

Causes

Ear infections are the most common cause of temporary hearing loss in children. Fluid may stay in the ear after an ear infection. The fluid can cause significant hearing problems in children. Any fluid that remains for longer than 8 - 12 weeks is cause for concern.

Causes that are present at birth (congenital):

• Birth defects that cause changes in the ear structures
• Genetic syndromes (more than 400 are known)
• Infections the mother passes to her baby in the womb (such as toxoplasmosis, rubella, or herpes)

Infections:

• Measles
• Meningitis
• Mumps
• Scarlet fever

Traumatic causes:

• Acoustic trauma such as from explosions, fireworks, gunfire, rock concerts, and earphones
• Age-related hearing loss (presbycusis)
• Barotrauma (differences in pressure, most often from scuba diving)
• Skull fracture (temporal bone)
• Traumatic perforation of the eardrum
• Working around loud noises on a day-to-day basis (can damage the cells responsible for hearing)

Other:

• Acoustic neuroma
• Blocked Eustachian tubes
• Buildup of wax in the ear canal
• Foreign body lodged in the ear canal
• Meniere's disease
• Scarred or perforated eardrum
• Use of certain medicines

Home Care

You can often flush wax buildup 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 stuck in the ear.

Take care when removing foreign bodies. Unless it is easy to get to, have your health care provider remove the object. Don't use sharp instruments to remove foreign objects.

See your health care provider for any other hearing loss.

When to Contact a Medical Professional

Call your health care provider if:

• Hearing problems interfere with your lifestyle
• Hearing problems do not go away or become worse
• The hearing is worse in one ear than the other
• You have sudden, severe hearing loss or ringing in the ears (tinnitus)
• You have other symptoms, such as ear pain, along with hearing problems
• You have new headaches, weakness, or numbness anywhere on your body

What to Expect at Your Office Visit

The health care provider will take your medical history and do a physical examination.

Medical history questions may include:

• Is the hearing loss in both ears or one ear?
• Is the hearing loss mild or severe?
• Is all of the hearing lost (inability to hear any sound)?
• Is there decreased hearing acuity (do words sound garbled)?
• Is there decreased ability to understand speech?
• Is there decreased ability to locate the source of a sound?
• How long has the hearing loss been present?
• Did it occur before age 30?
• What other symptoms are present?
• Is there tinnitus (ringing or other sounds)?
• Is there ear pain?
• Is there dizziness or vertigo?
• Do you have other family members with hearing loss?

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
• Caloric test
• CT scan of the head (if a tumor or fracture is suspected)
• MRI of the ear (see MRI of the head)
• Tympanometry
• X-ray of the head

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

References

Arts HA. Sensorineural hearing loss in adults. In: Cummings CW, Flint PW, Haughey BH, et al, eds. Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, Pa: Mosby Elsevier;2010:chap 149.

Lonsbury-Martin BL, Martin GK. Noise-induced hearing loss. In: Cummings CW, Flint PW, Haughey BH, et al, eds. Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, Pa: Mosby Elsevier;2010:chap 151.

Bauer CA, Jenkins HA. Otologic symptoms and syndromes. In: Cummings CW, Flint PW, Haughey BH, et al, eds. Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, Pa: Mosby Elsevier;2010:chap 156.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.