Newborn Audiological Evaluation
Newborns Hearing Tests
Newborns hearing tests are very different from the testing of older children or adults. For obvious reasons babys can not respond to either instruction or presented subjective testing. For this reason a suite of objective testing is used for newborns. The primary tests are Auditory Brainstem Response (ABR),Tympanometry, Acoustic Reflex and Auto Acoustic Emissions.
Auditory Brainstem Response (ABR)
The ABR is a test used to determine hearing loss in children who are either too young to respond or are unable to respond. It tells us how loud a sound must be for your child to hear it. What it does not do is tell us is if your child understands what he or she hears. An ABR is performed while your baby sleeps. This test can be performed under sedation or during natural sleep.
How is it performed?
The audiologist will scrub the skin where four electrodes will be placed (forehead and behind the ears). After the electrodes are in place, you may hold your child until he or she falls asleep. Once your child is sleeping, the audiologist will place small ear phones into his or her ears that will make a clicking sound. This sound travels from your child?s ears to the brain (through the auditory pathway) where it is recorded through the electrodes.
You will know the results of the ABR on the same day as the testing. Your audiologist will explain the results as well as recommend follow up appointments, if needed and send her report to your ENT.
How long does it take?
Under natural sleep, your child will be scheduled for two hours for the ABR to be completed. Your audiologist may complete additional tests at this appointment, such as Immittance tests and otoacoustic emissions (links). This group of tests (tympanometry and acoustic reflexes) measure how well your child?s middle ear works. These tests are commonly performed as they are sensitive to middle ear disorders. These tests do not require the child to respond.
An ear tip is placed in the canal that is connected to a machine that briefly varies the pressure in your child?s ear. Results from this test could indicate:
- Fluid in the middle ear (otitis media)
- Discontinuity of the ossicular chain (the three bones in the middle ear)
- Perforated eardrum
- Eustachian tube dysfunction
Acoustic Reflex Thresholds
This test measures how much the stapedius muscle in the middle ear contracts in response to a loud sound. This muscle acts as a protective mechanism that dampens loud sounds before they reach the cochlear (hearing organ). Absence or presence of acoustic reflexes for various presentations may be important in the differential diagnosis of both peripheral and central disorders of the auditory system such as vestibular schwannoma or facial nerve disorders.
This test measures how well your child?s cochlea, or inner ear works. The outer hair cells of the inner ear (cochlea) produce low level, inaudible sounds, called Otoacoustic emissions (OAE?s). OAE?s can either occur spontaneously or in response to clicks or tones. When the hair cells of the inner ear are stimulated, they respond by sending information to the brain and by sending an “echo” back to the outer ear. This “echo” is analyzed and recorded by the audiologist. OAE?s are usually present in individuals with a normal functioning cochlea but may be absent if even a mild conductive or cochlear hearing loss exists.
How it is performed
This test requires the child and everyone in the room to be very quiet for the measurement to be obtained. Your child will hear soft sounds played through a small ear phone. The response from the ear will be measured by a hand-held computer. This test only takes a few minutes to complete.
Why should my child have a hearing test?
On January 1, 2008, California implemented the Universal Newborn Hearing Screening Legislation, which requires hospitals to provide hearing screenings to every newborn. If the baby does not pass the newborn hearing screening, he or she will be referred for further testing with a pediatric audiologist.
All of our audiologists have received extensive training in pediatrics and are state-licensed and nationally certified. They perform these tests to determine if the baby has a hearing loss and if so, what degree (how much hearing loss) and type (what part of the auditory system is affected).
The younger a child is diagnosed with hearing loss and fit with amplification (hearing aids /cochlear implants) the better chances he or she has to learn language. Studies have shown that children that are amplified by 6 months of age can learn language similarly to their normal hearing peers.
Our goals for your child include
Providing appropriate amplification by the age of 3 months of age
To see the child enrolled in early intervention programs before 6 months of age
Please review our downloadable new Patients forms, download yours, fill it in and bring it along with you