Hearing Tests

Evidence 

https://doi.org/10.1016/j.ijporl.2022.111262 

Mirko Aldè, Federica Di Berardino, Umberto Ambrosetti, Stefania Barozzi, Gioia Piatti, Dario Consonni, Diego Zanetti, Lorenzo Pignataro, Giovanna Cantarella  

The prevalence of congenital hearing loss (HL) is approximately 1–3 per 1000 newborns, with a remarkable increase (3–6 per 100) in newborns admitted to the neonatal intensive care unit (NICU). Prematurity is considered a risk factor for HL, particularly if the gestational age (GA) is less than 32 weeks. 

National Framework for Neonatal hearing screening 

https://www.health.gov.au/resources/publications/national-framework-for-neonatal-hearing-screening 

Education  

Some babies are born with hearing problems. This happens in about 1 to 3 out of every 1,000 newborns. Babies in the Neonatal Unit have a higher chance of hearing loss - about 3 to 6 out of every 100. This is because being born premature can affect hearing, especially if the baby is born before 32 weeks. 

In the Neonatal unit, hearing tests might be done differently than in regular maternity wards. If your baby is unwell, the test may be delayed until they are well enough. But before your baby goes home, they should have a hearing test. 

Some babies have a higher chance of hearing problems because of: 

• Being born early (before 37 weeks) 

• Weighing less than 2500 grams (low birth weight) 

• Having certain medications (like gentamicin antibiotics used in NICU) 

• Severe jaundice 

• Infections during or after birth (like meningitis, or if the mother had an infection during pregnancy)

Types of hearing tests used in Neonatal Units

Otoacoustic Emissions (OAE) Test 

• This test checks if the inner part of your baby’s ear (the cochlea) is working properly. 

• A soft probe goes into the baby’s ear and plays clicking sounds. 

• The test measures sound waves produced by the ear in response. 

• The result is either pass or refer (which means another test is needed). 

• The test itself only takes a few minutes, but the whole process (getting baby ready, talking to parent, recording results) can take about 15–20 minutes. 

Automated Auditory Brainstem Response (AABR) Test 

• This test checks how the brain responds to sound and can find rare problems like auditory neuropathy. 

• Sounds are played through earphones or a small ear probe. 

• Small stickers (electrodes) are placed on your baby’s head to check how the brain reacts. 

• The test takes about 15–20 minutes, but more time might be needed if your baby is unsettled. 

Empowerment  

It's important for parents to remember that the newborn hearing test is only a screening test. If your baby does not respond as expected to the hearing test, they should be referred to an audiologist or ENT (ear, nose, and throat doctor) for further testing. That's why doctors and nurses don't say that a baby "failed" the hearing test; they say that he or she "referred" in one or both ears.  

Symptoms of a Hearing Loss  

Even if your newborn passes the hearing screening, continue to watch for signs that hearing is normal. Some hearing milestones your child should reach in the first year of life:  

• Most newborn infants startle or "jump" to sudden loud noises.  
• By 3 months, a baby usually recognises a parent's voice.  
• By 6 months, a baby can usually turn his or her eyes or head toward a sound.  
• By 12 months, a baby can usually imitate some sounds and produce a few words, such as "Mama" or "bye-bye."  

Useful Links 

Australasian Newborn Hearing Screening Committee 

https://www.newbornhearingscreening.com.au/parents/ 

Pregnancy, Birth and Baby 

https://www.pregnancybirthbaby.org.au/newborn-hearing-test 

Perth Children’s Hospital 

https://pch.health.wa.gov.au/Our-services/Newborn-Hearing-Screening-Program