Newborn Hearing Screening
Otoacoustic emissions found their largest role here: screening the hearing of newborn babies — a test quick enough, and passive enough, to run while an infant sleeps.
The 1-3-6 benchmark
Otoacoustic emissions found their largest role here: screening the hearing of newborn babies. The test is quick, needs no response from the baby, and can be done while the infant sleeps — which is why OAE screening has been adopted for newborns across most of the world.
The reason it matters is timing. A baby whose hearing loss is found and treated early develops markedly better language than one identified late. Screening exists to close that gap — to catch hearing loss in the first weeks of life rather than the first years[13].
Early hearing detection and intervention programmes are organised around three deadlines, known together as 1-3-6.
- Hearing screening complete by age 1 month
- Diagnostic audiologic evaluation by age 3 months
- Early intervention begun by age 6 months
The two-stage screen
Screening is not a single test but a pathway. An initial screen is performed — often only after the first 12 hours of life, so birth fluid and debris can clear the ear canal. A baby who does not pass is rescreened rather than immediately labelled. Only a baby who fails the rescreen is referred onward for full diagnostic assessment.
Two principles govern the pathway. A true pass requires both ears to pass within the same session — a one-ear pass is not a pass. And rescreening is deliberately limited: excessive re-testing raises the chance of wrongly passing a baby who does have hearing loss, so a persistent refer should move to diagnostic audiology, not into another round of screening.
Programmes aim to keep the refer rate low — commonly a target below about 4% — because every false refer means an anxious family and an unnecessary appointment[13].
OAE or automated ABR?
Two technologies screen newborns: OAE and automated auditory brainstem response (AABR). They test different parts of the pathway, and the difference is decisive. The OAE response is generated by the outer hair cells before the signal reaches the eighth nerve — a pre-neural response. AABR follows the signal onward along the nerve to the brainstem[13].
This is why an OAE-only screen has a blind spot. An infant with auditory neuropathy spectrum disorder has working outer hair cells and so passes an OAE screen — while AABR, which tests the neural pathway, correctly refers. An infant with ANSD screened by OAE alone is passed and lost to follow-up.
Why the NICU rule exists
Infants cared for in a neonatal intensive care unit are at substantially higher risk of neural hearing loss, including ANSD. For that reason many programmes mandate AABR — not OAE — as the screening method for NICU infants. The OAE simply cannot evaluate the auditory nerve or brainstem, so in the population most likely to have a neural lesion it is the wrong tool. A refer on an AABR screen should also not be “rescreened” with an OAE, since that would substitute a test that cannot see the suspected problem[13].
The combined approach
The strongest protocols use both tests rather than choosing between them — an application of the cross-check principle to screening. OAE screening is efficient and effective for detecting the cochlear and transient middle-ear losses common in well babies; AABR adds coverage of the neural pathway. Combining them lowers the false-refer rate and ensures auditory neuropathy is not missed[12].
Whichever protocol is used, screening is only the first step. A baby referred from screening still needs a full diagnostic evaluation — the screen says “look closer here”, not “this is the diagnosis”.