Pediatric Auditory Brainstem Response (ABR)
An auditory brainstem response (ABR) test measures auditory nerve reactions in response to sounds. ABR is not a hearing test itself, but it can be used to detect hearing loss in infants and very young children. ABR is considered one of the premier screening tests for newborns and infants under six months of age.
An audiologist may recommend your child for an ABR test due to the findings of an otoacoustic emissions (OAE) screening or other hearing test. Children who aren't old enough for behavioral tests such asvisual reinforcement or conditioned play audiometry may also be referred for an ABR test.
Tests & Diagnosis
Auditory brainstem response wave patterns can measure an infant’s hearing levels for certain speech frequencies. An ABR test is one of the best ways to diagnose hearing loss in infants. Only about 3% of babies are referred for further testing following an ABR test.
The Auditory Brainstem Response (ABR) test
A child must be asleep during the 1 to 2-hour ABR test. You should keep your baby up late the night before the test and wake her early. Older children need to be sedated for an ABR test.
The audiologist places small, sterilized electrodes (“stickers”) on your baby’s forehead and ears. The electrodes are connected to a computer that reads EEG activity. Earphones with neonatal ear tips (inserts) go inside your baby’s ear canals. The audiologist will play either “clicks” or a “tone burst” through the earphones.
- Clicks are a series of electronic impulses that cover a broad range of frequencies. Clicks are adequate for a hearing screening but they can’t measure information that is specific enough to prescribe hearing aids.
- Tone burst is a constant electrical signal. It usually provides the audiologist with enough information to recommend treatments.
Bone Conduction Auditory Brainstem Response (BCABR)
Bone conduction auditory brainstem response (BCABR) works in much the same way as standard ABR. In BCABR, bone conduction headphones replace the earphones. BCABR measures auditory responses by stimulating the cochlear.
Hearing problems are common in children. Nearly 6 in 1,000 children in the United States have some kind of hearing loss. If hearing loss is present at birth or occurs in early childhood, it can have a negative impact on speech and language development. Early screening, such as auditory brainstem response testing, can help identify problems and prevent hearing loss.
What an auditory brainstem response test measures
An auditory brainstem response test takes place in a sound-treated room within the hospital. Although ABR is non-invasive, your child must be asleep for the 1 to 2-hour test. An audiologist uses click and tone burst stimuli to determine a child's hearing sensitivity. The sounds may be delivered through earphones or special bone conductive headphones (BCABR). The ABR and BCABR tests identify your baby's auditory threshold over several frequencies.
What to expect
The best way to make sure your baby sleeps through the ABR test is to make sure he's tired and hungry. Parents should keep children up late the night before the appointment and wake them up early. The key is to make sure your baby is ready for a feeding and a nap at the time of the appointment. He will sleep either in a crib or your arms for the duration of the test. Children older than 6 months usually need sedation so they can sleep through the test.
Once the audiologist finishes collecting data, she will tell you if your child's hearing is fine or if he needs further testing. Only about 3% of infants are referred on for other hearing tests.
What is an auditory brainstem response test?
Auditory brainstem response tests measure a child’s hearing threshold over several frequencies. Audiologists can test and record by introducing low amplitude sounds into a child’s ear (or through bone conduction—BCABR) and the results are recorded to a computer.
Who is ABR testing designed for?
ABR tests are most often used on newborns and infants under 6 months of age. Your child may have been referred for an ABR test due to the results of an otoacoustic or similar test.
Are ABR and BCABR tests safe?
Despite the gadgets needed for ABR/BCABRtests (electrodes, earphones/headphones), they are non-invasive and completely safe. The procedure takes an hour or two while your child sleeps.
What do ABR and BCABR test for?
The tests can identify problems with your baby’s cochlear (inner ear) and the auditory nerves that travel from the cochlear to the brain.
What happens during an ABR (or BCABR) test?
While your child sleeps, the audiologist will place electrodes on your child’s forehead and ears, which send EEG readings to a computer. Low amplitude clicks and tone bursts are sent through the air (earphones) or bone conduction (headphones) to test your baby’s hearing threshold across a range of frequencies.
Is an ABR test conclusive?
ABR and BCABR tests are among the best tests available for hearing screening in newborns and infants. Only about 3% of children are referred for further testing upon receiving an ABR test.
How do I prepare my baby for an ABR test?
Your baby should be tired and hungry prior to the test. You should keep her up late and wake her early so she’s ready for a nap during the appointment.
This site provides a general description of ABRs.
American Speech-Language-Hearing Association
This page provides a detailed description of ABRs and how tests for this condition are conducted.
This site offers detailed descriptions of actual testing for ABRs.
This page thoroughly explains the assessment of ABR.
Michelle R. Petrak, Ph.D.