Neonatal hearing screening involves the objective determination of an individual’s inner ear functioning through means of an Oto-Acoustic Emission Test. If the inner ear and specifically the outer hair cells in the cochlea are functioning, it can be deduced that the baby has normal hearing. Any baby older than two days after birth can be tested!
If it happens that a baby refers the OAE screening test, twice, an auditory brainstem response test will be recommended. This diagnostic test will provide accurate results regarding the degree and type of hearing loss.
These results will be used to guide the hearing aid fitting. Remember intervention can never be too early!
The Auditory Brainstem Response (ABR) test is a helpful tool in determining a child’s ability to hear. The test uses a special computer to measure the way the child’s hearing nerve responds to different sounds. Three to four small stickers called "electrodes" will be placed on the child’s head and in front of his or her ears and connected to a computer. As sounds are made through the earphones, -the electrodes measure how your child’s hearing nerves respond to them.
The audiologist looks for certain neurological "markers" as your child’s hearing nerves respond to sounds. The softest intensity or loudness level at which these markers appear roughly corresponds to the child’s hearing level in that frequency range or pitch. By reading a computer printout of your child’s responses and interpreting these markers, the audiologist can tell if your child has a hearing problem.
Some Fast Facts about the Auditory Brainstem Response (ABR) Test:
- The ABR test measures the reaction of the parts of a child's nervous system that effect hearing (The ABR test measures the hearing nerve's response to sounds).
- The ABR test is safe and does not hurt.
- The ABR test can be completed only if the child is sleeping or lying perfectly still, relaxed and with his or her eyes closed.
- If your child is younger than 6 months of age, the ABR test usually can be done while he or she naps.
- If your child is older than 7 years, the ABR test usually can be done while your child is awake if he or she can relax and lie still.
- The test will be done in a special sound-treated suite in the Audiology department.
- For children between the ages of 6 months and 7 years, the ABR test is done under anaesthesia, which means that your child will need medication to help him or her sleep throughout the test.
- When anaesthesia is needed, there are special rules for eating and drinking that must be followed in the hours before the test. If these rules are not followed, the test cannot be done that day.
- When the test is done under anaesthesia, your child’s primary care provider will need to see your child for a physical in order to fill out a history and physical form.The test itself takes about 1 hour to 2 hours, but the entire appointment will take about 2 and a half hours without anaesthesia and up to 4 hours if your child needs anaesthesia, due to the recovery time.
The age of the patient will determine the process and procedures that will be followed.