What are the different types of hearing tests?
As part of a hearing evaluation, your child's health care provider
will do a complete medical history and physical exam. In addition, there
are many different types of hearing tests. Some of them may be used on
all ages, while others are used based on your child's age and level
of understanding.
Hearing tests for the newborn
There are 2 main types of hearing screening methods for newborns. These
may be used alone or together.
-
Evoked otoacoustic emissions (EOAE). A test that 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 otoacoustic emissions (responses) 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 usually takes just a few minutes, while the baby sleeps.
-
Auditory brainstem response (ABR). A test that uses electrodes (wires) 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 tests finds that your child has a hearing loss, further
testing is needed. It is advised that all babies with hearing loss be
identified by 3 months of age so that treatment can begin before the baby
is 6 months old, an important time for speech and language development.
Hearing tests for the infant
Evaluation of hearing in the infant may include the use of the above ?EOAE
and ABR tests. Also, the following may be used:
-
Behavioral audiometry. A screening test used in infants to observe their behavior in response
to certain sounds. Additional testing may be necessary.
Hearing tests for the toddler
Evaluation of hearing may include the above mentioned tests, along with
the following:
- Play audiometry. A test that uses an electrical machine to transmit sounds
at different volumes and pitches into your child's ears. Your child
usually wears some type of earphones. This test is modified slightly in
the toddler age group and made into a game. The toddler is asked to do
something with a toy (i.e., touch a toy, move a toy) every time the sound
is heard. This test relies on the cooperation of the child, which may
not always be given.
- Visual reinforcement audiometry (VRA). A test where the child is trained
to look toward a sound source. When the child gives a correct response,
the child is "rewarded" through a visual reinforcement such
as a toy that moves or a flashing light. The test is most often used for
children between 6 months to 2 years of age.
Hearing tests for the older child
Evaluation of hearing for the child older than 3 to 4 years may include
the above mentioned tests, along with the following:
- Pure tone audiometry. A test that uses an electrical machine that produces
sounds at different volumes and pitches in your child's ears. The
child usually wears some type of earphones. In this age group, the child
is simply asked to respond in some way when the tone is heard in the earphone.
- Tympanometry (also called impedance audiometry). A test that can be done
in most health care provider's offices to help determine how the middle
ear is functioning. It does not tell if the child is hearing or not, but
helps to detect any changes in pressure in the middle ear. This is a difficult
test to do in younger children because the child needs to sit very still
and not be crying, talking, or moving.