Hearing Screening Tests for Newborns
It's estimated that serious hearing loss occurs in about 2 to 3 of every 1,000 newborns.
Without screening or testing, hearing loss may not be noticed until the baby is more
than 1 year old. If hearing loss isn't found until later years, the brain's hearing
centers won't be correctly stimulated. This can affect hearing development and can
delay speech and language. Social and emotional development and success in school
may also be affected.
Most hearing loss is present at birth (congenital). But some babies develop hearing
loss after they are born. Hearing loss is more likely in:
Because of these risks, many health organizations now advise universal infant hearing
screening. Today nearly all newborns are screened for hearing loss. This allows earlier
treatment to prevent delays in language and development.
Types of testing
There are two types of hearing screening for newborns. They may be done before babies
leave the hospital but should be done before the baby is 1 month old. These may be
used alone or together:
-
Evoked otoacoustic emissions (EOAE). This test uses a tiny, flexible plug that is inserted into the baby's ear. Sounds
are sent through the plug. A microphone in the plug records the responses (otoacoustic
emissions) of the normal ear in reaction to the sounds. There are no emissions in
a baby with hearing loss. This test is painless and is often done in a few minutes
while the baby sleeps.
-
Auditory brainstem response. This test uses wires (electrodes) attached with adhesive to the baby's scalp. While
the baby sleeps, clicking sounds are made through tiny earphones in the baby's ears.
The test measures the brain's activity in response to the sounds. As in EOAE, this
test is painless and takes only a few minutes.
If the screening test shows a possible hearing loss, more testing is needed. Not all
babies who fail the first hearing test will be deaf or hard of hearing. Other things
may cause your baby to fail this early hearing test. These include excess fluid or
earwax in your baby's ear or too much noise in the room where your baby was tested.
All babies who don’t pass the screening test should be checked by a hearing specialist
(audiologist) by age 3 months. Treatment for hearing loss should start before the
baby is 6 months old, an important time for speech and language development.