Wednesday 22 July 2015

Hearing tests in children

Hearing tests in children are usually ordered by pediatrician or ENT doctor if the child presents with ear problems like infections or hearing and speech concerns expressed by parent or teachers.

However we need to be aware that newborn hearing screening is mandatory by law in the developed part of the world.1:1000 babies are born with some hearing problem and this ratio increases if the baby is high risker i.e. icu stay at birth,jaundice etc at birth.

So lets start with newborn hearing screening.For this screening we do Oto acoustic emissions,referred as OAE.
In this test a soft probe is gently inserted in baby's outer ear canal and the test is recorded.



Here is a test done in NICU,nurse is gently holding the probe and audiologist is performing OAE.
The test takes 2-3 minutes for both ears.It can be done in natural sleep.Here is a video



The test report of OAE is given as Pass or Refer.The refer ones are retested in 2-3 weeks.
If a baby fails OAE ,then ABER (Auditory Brainstem Evoked Response) or BERA is done.

ABER can be done in natural sleep in very young babies.Most of the children need oral sedation for this test.None of these test are painful,its just that even a swallow movement can intefere with the results.
Here are pictures of BERA test ,electrodes are taped over forehead and behind the ear with probes on each side.


Above test are both objective.As the baby grows,we can also do subjective tests.
Subjective tests are also done in newborns and below 18 months of age,but are not confirmative.
There are other subjective tests in children like Visual Reinforcement Audiometry.
Conditioned Play Audiometry
The commonest test used in clinical practice is Impedence audiometry or Tympanometry to rule out fluid in the ear or glue ear as well as eustachian tube block.This test again involves inserting a probe in outer ear canal and takes few seconds to give a recording:graphs as below
Image result for tympanometry results
So,in a nutshell all tests are safe.If any concerns,kindly meet your pediatrician and discuss.
Final word "Tests are not infallible, they are only as good as those taking, administering and interpreting them …”
If in doubt,observe the child and repeat the test.





Trust real doctors sitting in front of you, not internet....

  On Doctors day 1st July 2022, we can only wish for a healthy life and relationship for both patients and doctor. The first practical class...