How Is Hearing Loss Tested on Babies?
In Australia, one in 1000 babies is born with significant hearing loss each year. Thankfully, hearing loss can be identified early to plan support provisions and ensure each child affected develops at a standard pace. In fact, identifying hearing loss within a newborn ensures the best possible start to life as children can receive immediate assistance. The two common tests used to identify hearing loss in babies are the Otoacoustic Emissions Test (OAEs) and the Auditory Brainstem Response Test (ABR). Although for many new parents, the thought of running such tests may be concerning, these tests are perfectly safe and comfortable, and most importantly, reliable. However, not all hospitals run both tests, so it’s important to check whether these tests are available at a hospital before booking. Whether a hospital provides these tests depends on funds, personnel, and the number of babies born in the hospital. To ensure you have access to all the resources needed, it is sometimes better to see a hearing healthcare provider. If you do make a booking, you can ask for both tests to be performed or just one. Often, the OAE test is first conducted, and then if the baby does not pass, the ABR is performed. So, what does each test entail?
Otoacoustic Emissions Test
The OAE tests how effectively the inner ear, or cochlea, works. This is done by testing the ear’s otoacoustic emissions, which are sounds produced by the inner ear in response to sound. As sound travels through the ear and into the inner ear, tiny hairs that line the membrane of the inner ear vibrate. This vibration causes a very quiet sound to echo through the middle ear. This sound is the OAE that is measured. If you have average hearing, your ears will produce this sound; however, if your hearing loss is greater than 25-30 Decibels (Db), then you will not produce this sound.
This test is run by a small device that looks like a small earphone or probe, which is inserted into the ear of the baby. The earphone transmits sound into the ear and also measured the sound returned. The results of the test are displayed on the monitor, which is observed by the specialist running the test.
Auditory Brainstem Response Test
The ABR also tests the inner ear for its functionality, while also checking how if the brain’s pathways for hearing are working. This test is also sometimes called the Auditory Evoked Potential (AEP) test. It is performed on babies, small children, and anyone that may not be able to participate in a typical hearing test. One of the benefits of the ABR is that it can determine whether symptoms of hearing loss are caused by the brain or in a brain pathway, rather than by the ear. The test involves the placement of small electrodes on a baby’s head. These electrodes are connected to a computer that measures brain wave activity in response to sounds emitted from earphones. Again, the specialist conducting the test will see the results on the computer monitor.
For each of these tests, the sound is transmitted at one volume to only check whether the sound is actually being heard. These tests are performed with a pass or fail outcomes. Upon failing any of these tests, more tests are conducted to identify the specific conditions of the child’s hearing loss. If you’re the parent of a newborn, rest assured that resources are available to test for an accommodate hearing loss within your baby.
Attune is Australia’s leading independent provider of Hearing Healthcare. Attune perform tests on patients of all ages, from babies to senior citizens. If you’re in doubt about your hearing, book a test today.
