Most cases

of hearing loss develop very gradually so slowly that the person affected

often doesn't even notice the change in hearing.

Sudden hearing

loss occurs so quickly literally overnight or in an instant that the change

in hearing is dramatic and can be very upsetting.

A sudden hearing

loss can involve any part of the hearing system and something as straightforward

as ear wax or ear pressure following an airplane flight can cause a sudden

hearing loss.

However, the

term usually refers to a sudden "nerve" or sensorineural hearing

loss. The loss is almost always in one ear (unilateral), and is often

accompanied by some degree of dizziness or tinnitus (ear noises). Sudden

hearing loss is rare, occurring at a rate of about one case in 10,000

people each year.

Suspected causes

of sudden sensorineural hearing loss include viral infection, ototoxic

medications, acoustic trauma and meningitis. In most cases, the specific

cause is never found.

In cases with

no known cause, viral infection or vascular blockage is suspected. There

may be a history of a recent flu or cold, but in most cases there are

no other complaints (except perhaps dizziness, tinnitus or a sense of

"fullness" in the ear).

Partial of

complete recovery occurs in about 65 percent of the cases. Recovery can

take anywhere from a few days to a few months.

Those who seek

immediate medical attention (within a week or so) have a higher recovery

rate than those who wait.

The recovery

rate is also higher for those with milder hearing loss. Patients with

more severe dizziness are less likely to recover their hearing.

Someone who

experiences sudden hearing loss should seek medical attention as soon

as possible so that immediate treatment can be provided. The medical evaluation

usually includes a thorough history and physical, otologic and audiologic

examinations.