Why do we screen for hearing loss in babies?
The prevalence of hearing loss is significantly higher than other birth defects. In South Africa, it is estimated that 18 babies are born daily with some degree of hearing loss. Hearing loss is often described as the invisible birth defect. You often cannot see that a baby has a hearing loss. Babies do not always react to sound consistently and some of their reactions are reflexive, making judgement on hearing based solely on reaction unreliable. In the past, babies born with hearing loss were only identified as late as 2-5 years old when the children were not speaking. This means that children lost out on 2-5 years of speech and language development. The biggest reason that newborn hearing screening is conducted is that we want to identify and enrol babies born with hearing loss into early intervention programs as soon as possible. Infants identified, diagnosed and enrolled in early intervention services before the age of 6 months, have the potential to develop normal speech and language skills which aids in academic performance. The golden rule is “the earlier, the better”.
How do we screen for hearing loss?
The test used is called an Oto-Acoustic Emission or OAE screening test. It is a very quick, painless test. During this test, your baby will need to be quiet, asleep or sucking on a dummy, bottle or breast. A small probe is inserted into the ear. The machine sends sounds of 35dB (soft sounds), into the ear. If the cochlea is functioning, the hair cells in the cochlea produce an echo in response to the sounds. If the echo is recorded by the machine, the baby will pass the test which indicates normal cochlea functioning. If the echo is not recorded, the baby will refer the test.
What do I do if my baby does not pass the newborn hearing screening test?
Please do not panic. Sometimes, a baby will not pass the newborn hearing screening test as there is still amniotic fluid in their ears. This fluid blocks the ear and therefore we do not record the echo or OAE. In this case, it is important to wait 2-4 weeks, so that all the amniotic fluid drains out of the ears and then repeat the test. If your baby does not pass the test a second time, your baby will be referred for further diagnostic testing to see exactly why your baby isn’t passing the test.
How often should my baby receive hearing screening after they pass the first test?
It is recommended that children receive hearing screening yearly. However, if your baby was preterm, had a low birth weight, has a syndrome that is known to be associated with hearing loss or there is a family history of congenital hearing loss, then we will need to perform hearing screening every 3-6 months. If at any point in time you are worried about your child’s hearing, please contact us for a hearing screening test. If your child struggles with middle ear infections and if/or your child’s speech development is delayed, then we want to do a hearing test.
Newborn hearing screening is considered the standard of hearing care across many countries. I look forward to assisting you in performing your baby’s newborn hearing screening test.
Bronwyn van Wyk, Clinical Audiologist, M.Communication Pathology
Bronwyn consults at Midwives Exclusive on Tuesday Mornings. For more information or bookings contact us on: 012 327 3865