Newborn infant hearing screening programs are designed to identify hearing loss in infants shortly after birth. All states have implemented these screening protocols within hospitals and birthing clinics. Most hearing screening tests are done prior to discharge from the hospital or birthing clinics.
Typically, nurses or medical assistants are trained extensively on how to operate automated equipment for testing infants. Prior to discharge, each newborn has his/her hearing tested.
If, for some reason, the newborn does not pass the screen, a rescreen is usually done. If the infant does not pass the second hearing test, he/she is referred to a specialist for further testing.
Specialists who are experts at testing hearing are called audiologists. Audiologists have had training that emphasizes diagnostic hearing testing techniques as well as hearing rehabilitation of children and adults.
Their postgraduate academic training requires a minimum of a master’s degree.
Why do newborns need hearing screening?
Babies learn from the time they are born. One of the ways they learn is through hearing. If they have problems with hearing and do not receive the right treatment and early intervention services, babies will have trouble with speech and language development.
For some babies, early intervention services may include the use of sign language and/or hearing aids. Studies show that children with hearing loss who receive appropriate early intervention services by age 6 months usually develop good language and learning skills.
Some parents think they would be able to tell if their baby could not hear. This is not always the case. Babies may respond to noise by startling or turning their heads toward the sound.
This does not mean they have normal hearing. Most babies with hearing loss can hear some sounds but still not hear enough to develop full speaking ability.
Timing is everything. Your baby will have the best chance for normal language development if any hearing loss is discovered and treatment begins by the age of 6 months—and the earlier, the better.
How is newborn hearing screening done?
There are 2 screening tests that may be used:
Automated Auditory Brainstem Response (AABR)—This test measures how the hearing nerve responds to sound. Clicks or tones are played through soft earphones into the baby’s ears. Three electrodes placed on the baby’s head measure the hearing nerve’s response.
Otoacoustic Emissions (OAE)—This test measures sound waves produced in the inner ear. A tiny probe is placed just inside the baby’s ear canal. It measures the response (echo) when clicks or tones are played into the baby’s ears.
Both tests are quick (about 5 to 10 minutes), painless, and may be done while your baby is sleeping or lying still. One or both tests may be used.
What are some of the causes of hearing loss in the newborn?
Hearing loss in a newborn can be caused by a number of conditions. Some of the known risk factors include high bilirubin levels (jaundice), drugs that are toxic to the ears (for example, medicines that are given to the newborn to battle a serious infection may damage hearing as a side effect), prolonged mechanical ventilation, low Apgar scores, meningitis, prematurity, and/or low birth weight.
Malformed structures in the middle or outer ear can also lead to hearing loss. Viral illness during the pregnancy, such as rubella (German measles) or cytomegalovirus (CMV), can be passed to the newborn and result in hearing loss.
Hearing loss can sometimes be inherited in abnormal genes passed from the parents to the newborn or be the result of a gene mutation that occurred during fetal development.
Genetic counseling is often recommended for parents to determine if heredity is the cause of the hearing loss. In approximately half of all cases of hearing loss, the cause is never determined.
What if my baby does not pass the hearing screening?
If your baby does not pass the hearing screening at birth, it does not necessarily mean that your baby has hearing loss. In fact, most babies who do not pass the screening test have normal hearing. But to be sure, it is extremely important to have further testing.
This should include a more thorough hearing evaluation and a medical evaluation. These tests should be done as soon as possible, but definitely before your baby is 3 months old.
These tests can confirm whether hearing is normal or not. Be sure to talk with your child’s doctor about scheduling further testing.
If hearing loss is found, what can be done?
This depends on the type of hearing loss that your baby has. Every baby with hearing loss should be seen by a hearing specialist (audiologist) experienced in testing babies, a pediatric ear/nose/throat doctor (otolaryngologist), and a pediatric eye doctor (ophthalmologist).
Some children with hearing loss can also have problems with their vision. Many children are also seen by a geneticist to determine if there is a hereditary cause of hearing loss.
Special hearing tests can be performed by the audiologist who, together with the otolaryngologist, can tell you the degree of hearing loss and what can be done to help.
If the hearing loss is permanent, hearing aids and speech and language services may be recommended for your baby. Occasionally, surgical procedures may be helpful for hearing loss.
You will be informed of choices for communicating with your baby including total communication, oral communication, cued speech, and American Sign Language.
The Individuals with Disabilities Education Act (IDEA) requires that free early intervention programs be offered to babies and children with hearing loss, beginning at the time the child’s hearing loss is identified.
The outlook is good for children with hearing loss who begin an early intervention program before the age of 6 months. Research shows these children usually develop language skills on a par with those of their hearing peers.
What is the difference between a hearing screen and a diagnostic hearing test?
The basic difference between a diagnostic test and a hearing screen is the amount of information gathered during the session.
For example, if an infant fails the hearing screen, it is unknown if there truly is a hearing loss, how much hearing loss is present, or whether or not the hearing loss is permanent or correctable. A diagnostic test can usually answer these questions.
The diagnostic test session is understandably longer and requires more interaction with the infant. Typically, a more extensive ABR is conducted, using a variety of test stimuli. OAEs are also performed to cross-check the results of the ABR.
To complete a thorough test, the infant needs to sleep in the office for upward of 45 minutes. The more information that can be collected, the more complete the results will be.
If an infant does not pass a hearing screen in the hospital, what happens next?
Most hospital screening programs will refer infants who failed the initial screening test to a secondary center that specializes in more complete testing for diagnosis.
Sometimes, simple problems, such as too much residual amniotic fluid and vernix in the ear canal, will resolve prior to the rescreen and the infant will pass the second test.
The rescreen is an important step in determining whether the infant is able to hear, so it should not be taken lightly.
If an infant does not pass the rescreen, then a full diagnostic test will be necessary. This test may be completed at the rescreen site or at another facility, depending on several factors.