Newborn Hearing Tests

February 19, 2018February 19, 2018By

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In December 2017, The ZB Foundation was donated Newborn Hearing Test equipment by The Audiology Centre, Lahore. We will soon start this test in Pakistan. It is now time that we introduce this test to parents. With receiving this equipment, we stand with the deaf and hearing impaired communities in their struggle to gain empowerment.

“The results showed that Hearing Impairment was noticed in 33% cases during 0-6 months age but first professional advice was sought in the age bracket of 19-24 months in 35% cases” wrote Nazia Mumtaz and Shaista Habibullah of Isra University Islamabad in their recently published article. (Mumtaz, N., & Habibullah, S. 2017).

Why is a hearing test so important for a baby?

The ability to hear is the foundation of your baby’s ability to learn, so it’s important to identify any problems as soon as possible. That’s why experts recommend that your baby’s hearing be screened before he leaves the hospital. In fact, most hospitals do routine hearing tests for babies as part of their newborn screening. If you’re not sure whether your baby’s hearing was tested after birth, you should call and ask. If it wasn’t, or if your baby was born someplace without available testing, ask his doctor about hearing screening, preferably within the first month.

What causes hearing problems?

There are two types of hearing loss:

  • Congenital (meaning the baby was born with it) and,
  • Acquired (meaning the baby lost hearing sometime after birth).

Sometimes hearing impairment is inherited – even if both parents have normal hearing. Other times a baby’s hearing is damaged because his mother had a viral infection during pregnancy, such as German measles (rubella), toxoplasmosis, or herpes.

Some children are born with impaired hearing because of low birth weight or premature birth, or abnormal inner ear development. In some cases, there’s no explanation. After birth, a child may suffer hearing loss when the nerves in his inner ear are damaged by an injury, a tumor, or an infection such as chicken pox, the flu, meningitis, or mononucleosis. Medications such as chemotherapy agents, salicylates, loop diuretics, and certain intravenous antibiotics may also cause hearing loss. Hearing loss can also be caused by fluid retained in the middle ear – after infection or because of poor ventilation of the ear. This fluid can remain in the ear for weeks, even after an infection is gone, says David H. Darrow, professor of otolaryngology and pediatrics at Eastern Virginia Medical School in Norfolk. The fluid can cause temporary hearing loss until the fluid clears or is surgically removed. (It’s hard to hear through an ear filled with fluid.) Permanent hearing loss from fluid is rare, but it can occur in children whose fluid remains untreated, resulting in structural changes in the eardrum or hearing bones. Earwax and foreign objects in the ear can also cause temporary hearing loss.

 

What’s the screening test like?

Two types of newborn hearing screening tests are used: automated auditory brainstem response (AABR) and otoacoustic emissions (OAE). Each takes only five or ten minutes and is perfectly painless. Many babies sleep through the screening. To do the AABR test, a nurse places sensors, connected to a computer, on your baby’s scalp. These sensors measure your baby’s brainwave activity in response to little clicking sounds that are transmitted through small earphones. The test is simple, painless and not dangerous.

 

What happens if a baby doesn’t pass the test?

If your baby doesn’t pass the screening at birth, it doesn’t necessarily mean that he has a hearing problem, but it does mean that more testing is necessary. It’s important that your baby be scheduled for a repeat screen within the first month of life. Babies sometimes fail the first screening because they have fluid in the middle ear or debris (like vernix) in the ear canal, or because the room is too noisy or they’re too feisty during the test (moving or crying). Many babies who fail the first screening go on to pass follow-up testing.

 

If a baby passes the hearing test, could he still have hearing loss?

Yes. The newborn screening tests don’t detect mild degrees of permanent hearing impairment, so passing the newborn hearing screening doesn’t mean that a baby’s hearing is perfect. It’s very possible for a baby to pass the newborn hearing screening but either have a mild hearing loss or develop a hearing loss later. Delayed-onset hearing loss can happen for a number of reasons – including illness, injury, genetics, or exposure to loud and prolonged levels of noise. That’s why it’s important to have your baby’s hearing checked regularly, at every well-baby checkup.

 

Won’t I be able to tell if my baby can’t hear?

Not necessarily. There are degrees of hearing loss, and you may or may not detect that there’s a problem. Your baby may turn toward you when you talk or enter the room, but this doesn’t mean that his hearing is fine. He may be able to hear some sounds, but miss enough that his ability to learn to speak would be affected. Here are some guidelines for what to expect in a child with normal hearing:

  • Your newborn startles when he hears a loud sound.
  • At around 2 months of age, he becomes quiet when he hears your voice.
  • When he’s 4 or 5 months old, he’ll look toward a loud sound.
  • At 6 months, he begins to imitate sounds and babble.
  • At around 9 months, he’ll turn toward a softer sound.
  • By 1 year, he responds to music and says “ma-ma” and “da-da.”

 

How is a hearing screen different from an audiologic evaluation?

Hearing screening is a quick way to determine whether or not there is a possibility of a hearing loss. If your baby does not pass the hearing screen, additional testing by an audiologist (hearing expert) is needed. A complete evaluation by an audiologist is the only way to know for sure that your baby is hearing all the sounds important for speech and language development.

 

Is it OK to wait until my baby is older before I schedule follow-up testing with an audiologist?

No. Prompt follow-up, ideally between 2-4 weeks of age, ensures that your baby will sleep long enough to complete the needed testing. Babies who do have a permanent hearing problem have better speech and language outcomes the earlier the problem can be detected.

 

What can I do to help prevent hearing loss in my baby?

While a baby will sometimes have hearing loss because of genetics or an unavoidable condition, there are things you can do to minimize the risk from other factors:

  • Never insert anything into your baby’s ear canal. Even cotton-tipped swabs can cause damage.
  • Immunize your baby against childhood diseases, because some of these – like mumps– can cause hearing loss.
  • Monitor your baby’s colds and ear infections. If your baby shows signs of having an ear infection, talk with his doctor.
  • Don’t expose your baby to noise that’s too loud, especially ongoing noise. If you have to raise your voice to be heard over the noise, then it’s too loud. Carpeting and area rugs help soften indoor noise.

 

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