For infants, young children, or anyone unable to reliably participate in traditional behavioral hearing tests, a specialized category of objective diagnostic tools becomes essential: Otoacoustic Emissions (OAE) testing and Auditory Brainstem Response testing (ABR, sometimes referred to as BERA — Brainstem Evoked Response Audiometry). These tests don’t require any active response from the patient, making them invaluable for newborn hearing screening and complex diagnostic cases alike.
What Is OAE Testing?
Otoacoustic emissions are faint sounds produced by healthy inner ear hair cells in response to sound stimulation — essentially, tiny “echoes” generated by a properly functioning cochlea. OAE testing uses a small, soft probe placed in the ear canal to play sounds and measure whether these echo responses are present.
The presence of clear OAE responses generally indicates that the outer hair cells of the cochlea are functioning normally. Absent or reduced OAE responses can indicate hearing loss, though further testing is usually needed to determine the exact nature and degree.
Why OAE Testing Is So Valuable
OAE testing offers several distinct advantages:
- It’s quick, typically taking just a few minutes per ear
- It requires no active participation or response from the patient
- It’s completely non-invasive and painless
- It can be performed even on sleeping infants
- It provides objective, physiological data rather than relying on subjective responses
These qualities make OAE testing a cornerstone of universal newborn hearing screening programs worldwide, allowing hearing concerns to be identified within days of birth rather than months or years later.
What Is ABR/BERA Testing?
Auditory Brainstem Response (ABR) testing, also known as BERA, measures electrical activity generated by the auditory nerve and brainstem in response to sound stimuli. Small electrodes are placed on the scalp and earlobes, and clicking or tonal sounds are played through earphones while the resulting neural responses are recorded and analyzed.
Unlike OAE testing, which primarily assesses cochlear (inner ear) function, ABR testing evaluates the entire auditory pathway from the inner ear through the auditory nerve to the brainstem — providing crucial information about neural transmission, not just cochlear health.
Key Applications of ABR/BERA Testing
Newborn and Infant Hearing Assessment
ABR testing is often used alongside or following OAE testing in newborn hearing screening programs, particularly to confirm results or provide more detailed diagnostic information when OAE results are inconclusive or abnormal.
Diagnosing Auditory Neuropathy Spectrum Disorder
This is a particularly important application: some children have normal OAE responses (indicating healthy cochlear hair cells) but abnormal ABR responses, suggesting a problem with how sound signals are transmitted along the auditory nerve. This specific pattern is characteristic of auditory neuropathy spectrum disorder, a condition that would be missed entirely if only OAE testing were performed.
Estimating Hearing Thresholds in Difficult-to-Test Patients
For infants, young children, or individuals with developmental differences who cannot reliably participate in behavioral audiometry, ABR testing can estimate hearing thresholds objectively, providing critical diagnostic information that guides early intervention.
Assessing Auditory Nerve and Brainstem Function
Beyond hearing threshold estimation, ABR testing is also used in certain neurological and medical evaluations to assess the integrity of the auditory nerve and brainstem pathways.
Why These Tests Work Best Together, Not in Isolation
This is a crucial point that’s often misunderstood: OAE and ABR testing assess different parts of the auditory pathway, and relying on just one can lead to incomplete or even misleading conclusions. A comprehensive audiological evaluation for infants and difficult-to-test patients typically combines both tests, along with tympanometry and, when age-appropriate, behavioral testing — building a complete picture of auditory function from the outer ear all the way to the brainstem.
This layered, comprehensive approach to diagnostic testing — rather than relying on a single isolated test — reflects the kind of thorough audiology care that leads to accurate, timely diagnoses. This overview of Soft Hear’s specialized OAE, BERA, and ABR testing services as part of a complete audiology evaluation explains how these advanced diagnostic tools are integrated into a broader clinical assessment for infants, children, and complex diagnostic cases.
Why Early Detection Through These Tests Matters So Much
Hearing plays a foundational role in speech and language development during the earliest years of life. Research consistently shows that early identification and intervention for hearing loss — ideally within the first few months of life — leads to significantly better speech, language, and cognitive outcomes compared to later identification. This is the driving principle behind universal newborn hearing screening programs, which rely heavily on OAE and ABR testing precisely because these tools can objectively assess hearing in infants who obviously cannot respond to a traditional hearing test.
What Happens If Results Are Abnormal?
If OAE or ABR testing suggests hearing loss or auditory dysfunction, further diagnostic testing and referral to a pediatric audiologist or ENT specialist is typically recommended to confirm the diagnosis, determine severity, and begin appropriate early intervention — which may include hearing aids, cochlear implant evaluation, or other rehabilitative and educational support services depending on the specific findings.
Final Thoughts
OAE and ABR/BERA testing represents some of the most important advances in objective hearing assessment, particularly for infants and difficult-to-test populations. When used together as part of a comprehensive evaluation, they provide critical diagnostic information that can dramatically improve outcomes through early, accurate identification of hearing concerns.