Tympanometry tests the movement of the eardrum when an ear
infection or other middle ear problem is suspected. A doctor places the tip of
a handheld tool into the child's ear. The tool changes the air pressure inside
the ear and produces a clear tone. Then the tool measures how the eardrum
responds to the pressure and the sound. The results of this test are used to
help figure out what is going on in the ear.
Why It Is Done
The results of tympanometry can tell doctors whether there is fluid
behind the eardrum or whether an ear tube is blocked. The test can also
discover whether there is a hole in the eardrum. This information helps doctors
decide what kind of treatment your child may need.
Normally the eardrum moves easily when pressure in the ear canal is
changed. Most of the time, if the test is normal, there is no fluid behind the
When the eustachian tube, which connects the back of the nose and
throat with the middle ear, is not working well, the eardrum does not move as
it should. But in some cases the test shows fluid behind the eardrum when
there really is none.
What To Think About
If the child is crying or unable to hold still, tympanometry may be
difficult or impossible to do. Crying and movement can cause incorrect results.
Earwax can also cause false results. If there is a lot of earwax, it may be
cleared out before the test begins. This test may not be useful for babies
younger than 7 months because the results can be misleading.
Before the test, let your child know what is going to happen. This
will help keep your child calm and still during the test. At home before the
test, you can play "pretend ear exam" so your child can practice sitting still.
Also, explain that loud noises are part of the test.