Newborn hearing screening uses quick, painless tests that measure how your baby’s ears and auditory system respond to sound. Most hospitals perform the screening within 24 to 48 hours of birth, often while your baby sleeps. The entire process typically takes just a few minutes per ear, and your baby won’t need any special preparation.
The Two Tests Used for Screening
Hospitals use one or both of two tests: otoacoustic emissions (OAE) and automated auditory brainstem response (AABR). They measure different parts of the hearing system, and neither requires your baby to do anything at all.
Otoacoustic Emissions (OAE)
For this test, a technician places a small, soft earphone into your baby’s ear canal. The device plays quiet sounds and then listens for an “echo” that healthy inner ears naturally produce. Tiny hair cells inside the inner ear vibrate in response to sound, and those vibrations create a faint signal that bounces back out. The earphone picks up that signal and records it. If there’s no echo, it may indicate hearing loss.
OAE is specifically measuring the function of the outer hair cells in the inner ear. It confirms that this part of the ear is detecting sound, but it doesn’t test whether the signal is traveling successfully along the auditory nerve to the brain. That distinction matters, because a condition called auditory neuropathy, where the ear detects sound but can’t transmit it properly to the brain, can be missed by OAE alone.
Automated Auditory Brainstem Response (AABR)
AABR goes a step further. A technician applies small sticker electrodes to your baby’s head and ears, using a bit of gel to help them stick. Then soft earphones play clicking sounds while the electrodes measure your baby’s brain activity in response. A computer records whether the auditory nerve and brainstem are picking up and processing the sounds correctly.
Because AABR tracks the signal all the way from the ear to the brainstem, it can detect auditory neuropathy and other nerve-related hearing problems that OAE would miss. Many hospitals use both tests together, especially for babies who spent time in the NICU or have other risk factors.
What Happens During the Test
Both tests work best when your baby is calm and still. Most screening programs aim to test while the baby is sleeping or drowsing after a feeding. The room should be reasonably quiet, since background noise can interfere with the sensitive measurements. You don’t need to do anything to prepare your baby, though feeding beforehand often helps them settle.
The OAE test takes about two to five minutes. AABR can take slightly longer because the electrodes need to be placed and the computer needs enough data to read the brainwave patterns clearly. Neither test involves any discomfort. Your baby may not even wake up.
Understanding the Results
Results come back as either “pass” or “refer.” A pass means the ear responded normally at the levels tested. A refer means the test didn’t pick up a clear enough response, and further evaluation is needed.
A refer result does not automatically mean your baby has permanent hearing loss. One common reason for a refer is leftover vernix (the waxy coating from the womb) or fluid in the ear canal or middle ear. This is especially common in babies tested within the first few hours of life, before that fluid has fully drained. In many cases, a retest a few days or weeks later comes back normal.
If your baby gets a refer on the OAE, some hospitals will immediately follow up with an AABR to get a more complete picture. If the AABR also comes back as a refer, a full diagnostic hearing evaluation is scheduled, ideally within the first few months of life.
The 1-3-6 Timeline
National guidelines from the CDC recommend a specific timeline for catching and addressing hearing loss early. It’s known as the 1-3-6 benchmarks:
- By 1 month: Your baby should be screened for hearing loss, which typically happens before hospital discharge.
- By 3 months: Babies who didn’t pass the initial screening should receive a full diagnostic evaluation with an audiologist.
- By 6 months: Babies confirmed to have hearing loss should be enrolled in early intervention services, which may include hearing aids, speech therapy, or other support.
This timeline exists because early intervention has an outsized effect on language development. Children who receive hearing support before six months of age develop communication and language skills that track much more closely with their hearing peers than children identified later.
Why Universal Screening Matters
Permanent bilateral hearing loss affects roughly 1.33 out of every 1,000 babies born. That may sound rare, but it makes hearing loss one of the most common conditions detectable at birth. Before universal screening programs, many children weren’t identified until age two or three, when delayed speech finally raised concerns. By then, critical windows for language development had already narrowed.
Universal screening catches hearing loss in babies with no obvious risk factors. About half of newborns with hearing loss have no family history or other warning signs, which is why testing every baby, not just those considered high risk, became the standard approach. In the United States, nearly all states now mandate newborn hearing screening before hospital discharge.
What a Follow-Up Evaluation Looks Like
If your baby is referred for a full diagnostic evaluation, the audiologist will likely perform a diagnostic ABR. This is a longer, more detailed version of the screening AABR. Your baby will need to be asleep for it, sometimes with the help of mild sedation for older infants who won’t sleep on their own during the test. The audiologist uses the results to determine the type and degree of hearing loss in each ear.
Depending on the findings, next steps could range from monitoring (if the loss is mild or likely temporary from fluid) to fitting hearing aids or exploring other interventions. The goal is always to have a clear plan in place before that six-month benchmark, so your child’s language development stays on track from the start.