- Automated Auditory Brainstem Response (AABR): It is a test that checks the brain’s response to sound.
During this test, your newborn wears tiny earphones that play sounds and, along with three electrodes placed on her scalp, they will measure brain activity as she listens. The child being tested can be sound asleep during the test. It takes around 10-15 minutes to perform, and results are automatically generated.
- Otoacoustic Emissions (OAE): This test uses a tiny probe that is inserted just at the entrance to your baby’s ear canal and emits a number of sounds. The test checks for echoes in your baby’s ears in response to the clicks or tones that are played. Baby can be sound asleep and the testing takes 5-10 minutes. The results are automatically generated.
- Audiological Evaluation: An audiological evaluation, sometimes called a hearing assessment, is a group of tests that check different parts of the hearing system to identify how well the baby can hear. The results of the evaluation are put on a graph called an audiogram which shows the areas of hearing loss (low, middle or high-pitched sounds) and degree of hearing loss (mild, moderate, severe, or profound).
- Difference between a Hearing Screening and a Diagnostic Hearing Evaluation
The purpose of the hearing screening is to quickly test one part of the hearing system to find out whether it is working properly. The OAE screening measures the function of the outer hair cells but does not measure a response from the auditory (hearing) nerve. The AABR screening tells us how the nerve and brainstem pathways for hearing are working. (See the section above on “Types of Hearing Tests” for screening details.) Diagnostic hearing testing uses the same methods of testing but checks more frequencies and levels. Screening takes less than 10 minutes, diagnostic testing is more detailed and takes two to three hours because all parts of the hearing system are checked. Testing is done while the baby is asleep. It may take more than one appointment to get all the testing done. Your audiologist- a person trained to check hearing, can explain all the tests, why they are being done, and what was found.