Hearing Tests in Newborns

Hearing loss is a serious problem that may not be obvious in newborns and infants. Babies with hearing loss are unable to communicate either verbally or non-verbally and respond to oral commands. As the child grows, the general development of the child gets affected and she may develop behavioral problems. Decreased hearing can affect the development of the auditory nervous system. This, in turn, can affect speech perception, which could interfere in the later social life of the individual, affecting his/her educational achievements, ability to get a good job and be economically self sufficient.

Though studies indicate a high prevalence of hearing loss in children in India, screening with hearing tests for newborns are not yet routinely carried out in India.

Health Animation - Anatomy of the Ear and Hearing

The anxious parents may subject the child to various tests to diagnose the condition.  A simple hearing test in such circumstances may help to diagnose any hearing problem in the infant.  Thus, routine screening with hearing tests in newborns could help to detect and treat any hearing problem early and keep the overall development of the child on tract.

Permanent hearing loss occurs in around one to two out of every 1000 children.  Nearly half of newborns with hearing loss do not have any risk factors which can predetermine if they are likely to suffer from hearing loss.  Others may have one or more risk factors, some of which are listed below:

Admission in the Intensive Care Unit for more than 2 days

History of hereditary hearing loss in the family

Structural abnormalities in the head and face

Certain syndromes present from birth like Usher syndrome and Waardenburg syndrome

Infections acquired while the baby is still in the uterus like cytomegalovirus, toxoplasmosis, bacterial meningitis, syphilis, herpes, and rubella (German measles).

Screening with Hearing Tests

Who should undergo screening with hearing tests?

Current recommendations indicate that all newborns before the age of 1 month should undergo screening with hearing tests. If the screening test detects a decrease in hearing, a complete audiological examination should be done before the baby is 3 months of age. Children at high risk for developing hearing loss should undergo regular monitoring till the age of 3 years.

What are the tests done to check for hearing during screening?

The following tests are used for screening for hearing loss:

Otoacoustic emissions (OAEs): This is a reliable test that detects even mild hearing loss.  It can be performed by a non-audiologist as well.  A small probe is inserted into the ear canal of the baby and is connected to the recorder in a quiet room.  A small sound like a click serves as the stimulus. This results in minute vibrations in a normally functioning inner ear, which are picked up by the probe.  The test can be performed in as less as a few seconds. Sometimes, debris or fluid in the ear may result in a wrong diagnosis.  In such cases, the test could be repeated or the auditory brainstem response test can be performed.

Auditory brainstem response (ABR) test:  This test is done in those who failed the otoacoustic emissions test.  During this test, an electrical response is evoked in response to a click stimulus introduced to earphones placed in the ears, which is recorded using electrodes placed on the head of the baby.  The baby may require sedation for this test.

FAQs

1. Which doctor should I visit to get a hearing test done for my baby?

If you wish to get a hearing test done for your baby, you should visit your baby’s pediatrician who will refer you to an audiologist to do the tests.

2. What happens if my baby has a hearing problem?

If your baby has been found to have a hearing problem, treatment will depend on the individual case. Some cases may require surgery.  Some may require hearing aids.  Communication skills will also have to be taught to the infant and parents as the baby grows up.

3. Do the hearing tests have any complications?

The hearing tests themselves do not have any complications.  Using screening tests for hearing may cause undue anxiety in the parents if the test results come positive when a hearing defect is actually absent.   Surgeries for hearing loss detected during screening may be associated with complications like meningitis.

Screening for hearing requires specific equipment and well-trained staff to ensure accurate results.  Adequate numbers may be difficult to arrange for to ensure widespread screening.