Here’s how a newborn hearing screening is performed
In the first few days of a baby’s life, they will undergo various tests to identify and rule out conditions that can affect long-term health. One of these important tests is the universal newborn hearing screening. It’s used in many countries across the world to identify both unilateral and bilateral hearing loss. In cases of significant hearing loss, this approach allows for early hearing amplification to maximize the child’s speech and literacy.
The screening is typically performed on the first day of life or before discharge from the hospital after birth. This creates a standardized method of testing that ensures no infant is missed.
There are two methods of screening:
1. Otoacoustic emissions (OAEs): This quick method involves inserting a small probe into the ear canal that emits a sound and records the response of the outer hair cells of the cochlea. A child can either “pass” if the response is recorded, or “refer” if the response is not present.
2. Automated auditory brainstem response (AABR): This involves placing disposable surface electrodes on the forehead to record brain wave activity in response to sound. It allows for the identification of a problem along the entire hearing pathway, from the cochlea to the brainstem. A child can either “pass” or “fail” this test depending on the recorded activity.
Some screening programs involve combinations of these methods.
Causes of newborn hearing loss
There are many causes of newborn hearing loss, including genetic and environmental factors. Part of the work-up of hearing loss in a newborn may involve genetic testing, laboratory testing and imaging studies such as CT scan or MRI. This can be overwhelming for families which is why your child’s care team will work in a coordinated approach with other specialists including audiologists, geneticists, radiologists and speech language therapists to ensure that a child’s needs are addressed.
What happens after a failed screening?
Children who fail in-hospital screening testing are referred for repeat testing between 2-8 weeks after discharge. A positive test at this second stage generates a referral to audiology for a diagnostic ABR completed in the natural sleep state prior to 3 months of age. The findings of this may lead to a pediatric otolaryngology (ENT) referral for further evaluation. The team of audiologists and ENT providers will use the information contained within the hearing test as well as exam findings to determine the type and severity of hearing loss. Next steps may involve observation, fitting for a hearing aid or steps toward surgery such as cochlear implantation.
Children whose hearing loss is identified and addressed before 6 months of age may go on to develop speech and language skills similar to their peers. This is why it’s important that hearing tests are performed early in life and that affected children are appropriately referred.
About the Author
Dr. Rebecca Compton is an otolaryngologist at Advocate Children’s Hospital.