A newborn hearing screening is a quick, non-invasive procedure designed to check an infant’s hearing ability shortly after birth. This universal public health measure identifies potential hearing loss as early as possible. Early detection is time-sensitive because a baby’s brain begins developing speech and language pathways immediately upon exposure to sound. Identifying hearing differences early allows for timely intervention, which significantly improves a child’s long-term speech, language, and communication development.
The Two Primary Screening Methods
Two main types of objective physiological tests are used to screen newborns for hearing function. Both methods are painless and generally performed while the baby is sleeping or resting quietly. The first method is called Otoacoustic Emissions, or OAE, which measures a response generated within the inner ear.
The OAE test involves placing a miniature earphone and microphone into the baby’s ear canal. The earphone emits soft sounds, and the microphone records a faint echo that healthy inner ears naturally produce in response to stimulation. This echo, or otoacoustic emission, originates from the outer hair cells in the cochlea, which vibrate when functioning normally. If the microphone detects the echo, the cochlea is responding appropriately to sound.
The second method is the Automated Auditory Brainstem Response, or AABR, which evaluates the entire auditory pathway from the ear to the brainstem. For this test, small electrodes are placed on the baby’s head and neck, and soft earphones are placed over or in the ears. These electrodes measure the electrical activity produced by the auditory nerve and brainstem in response to clicking sounds played through the earphones.
The AABR test confirms that sound signals are not only registered by the inner ear but are also successfully traveling along the auditory nerve to the brain. This test is often preferred for babies who spent time in the Neonatal Intensive Care Unit (NICU) because it assesses a broader part of the hearing system. Both OAE and AABR tests provide a simple “Pass” or “Refer” result, indicating whether further diagnostic testing is needed.
When and Where the Screening Occurs
The initial hearing screening is a standard part of newborn care and is nearly always completed before the infant is discharged from the hospital. Most screenings occur within the first 24 to 48 hours after birth. Performing the test early ensures that families receive the initial result before leaving the medical facility.
The timing is chosen to maximize the chances of the baby being calm or asleep, which helps ensure accurate test results. If a baby is born at home or in a birthing center outside of a hospital setting, the parents must arrange for an outpatient screening. In these cases, the procedure should still be completed promptly, ideally within the first month of life.
The screening is quick, often taking only a few minutes per ear. If the initial attempt is unsuccessful, a rescreening is typically attempted later, sometimes just hours before discharge.
Understanding Results and Follow-Up Steps
The result of a newborn hearing screening will be either a “Pass” or a “Refer” for each ear. A “Pass” indicates the baby responded appropriately to the screening sounds and does not require immediate follow-up testing. Even with a pass, parents should remain attentive to their child’s hearing milestones and discuss any future concerns with their pediatrician, as some types of hearing loss can develop later.
A “Refer” result, sometimes called “Did Not Pass,” does not mean the baby definitely has permanent hearing loss. It simply means the screening test could not confirm a clear response and requires further investigation. Temporary factors, such as fluid or vernix remaining in the ear canal after birth, are common reasons for a “Refer” result. In some cases, a baby who refers in the hospital will simply pass a second screening days or weeks later once any residual fluid has cleared.
Following up immediately after a “Refer” result is important to determine the exact cause. Delaying this next step can have a significant impact on a child’s development. Audiologists and pediatric health programs adhere to a public health guideline known as the “1-3-6 rule.”
The “1-3-6 rule” specifies that all babies should be screened for hearing loss by one month of age. If a baby receives a “Refer” result, they should have a comprehensive diagnostic audiology evaluation by three months of age. This evaluation determines whether hearing loss is present and, if so, the type and severity.
If the diagnostic evaluation confirms hearing loss, the third part of the rule requires the baby to be enrolled in early intervention services by six months of age. These services connect families with resources and professionals to maximize the child’s speech and language acquisition. Adherence to the 1-3-6 timeline is important because the first six months of life represent a foundational period for auditory brain development.
The diagnostic evaluation following a “Refer” result is much more detailed than the initial screening. This comprehensive assessment is performed by a pediatric audiologist. The audiologist will perform a full battery of tests to confirm the nature of the hearing response, ruling out temporary issues and determining if any permanent hearing loss is present. Timely completion of this diagnostic step is the bridge between a simple screening result and the actionable intervention needed to support a child’s developmental trajectory.