The Newborn Hearing Screening (NHS) is a common, non-invasive procedure designed to check a baby’s hearing shortly after birth. This quick screening is typically administered before a newborn leaves the hospital or birthing center. The goal is to quickly identify infants who may have hearing levels outside the typical range, which is important for ensuring a child can access the sounds necessary for communication development.
The Necessity of Early Detection
The first few years of life represent an accelerated window for language acquisition and speech development. From the moment a baby is born, they begin learning language by hearing the sounds and speech around them. This period of heightened neural plasticity means that prompt auditory exposure is highly beneficial for developing communication skills.
Undetected hearing loss can significantly interrupt this process, leading to delays in language, speech, and communication abilities. Without timely intervention, a child may experience long-term impacts on academic performance, social interactions, and cognitive development. Identifying hearing differences early, ideally before three months of age, allows treatment to begin before six months. This helps children achieve speech and language milestones comparable to their peers. About three to six out of every 1,000 newborns have some degree of hearing loss, highlighting the importance of universal screening.
How the Screening Tests Are Performed
The Newborn Hearing Screening uses objective testing methods that do not require active participation from the baby. The two primary tests used are Otoacoustic Emissions (OAE) and Automated Auditory Brainstem Response (AABR), which can be used alone or together. Both tests are safe, painless, and are often performed while the infant is sleeping or resting quietly.
The OAE test assesses the function of the cochlea, the inner ear organ. During this procedure, a small probe containing a speaker and a microphone is placed gently into the baby’s ear canal. The speaker plays soft sounds; if the cochlea is functioning normally, it produces a faint “echo” response recorded by the microphone. If this echo is absent or reduced, it may indicate a hearing loss.
The AABR test evaluates how the auditory nerve and brainstem respond to sound, measuring the path from the ear to the brain. Electrodes are placed on the baby’s head, typically on the forehead and behind the ears. Soft clicking sounds are sent through small earphones, and the electrodes measure the electrical signals generated by the hearing nerve and brainstem in response to the sound. This test provides information about the softest level of sound the ear can hear and is less affected by middle ear fluid than the OAE test.
Interpreting Results and Next Steps
The screening results are categorized into two immediate outcomes: “Pass” or “Refer” (sometimes called “Did Not Pass” or “Fail”). A “Pass” result suggests that the baby’s hearing is likely typical at the time of the screening. Even with a passing result, parents should monitor their child’s auditory and language milestones, as some hearing loss can develop later in childhood.
A “Refer” result means the baby requires further testing; it does not confirm a permanent hearing loss. Reasons for a “Refer” can include temporary issues like fluid in the ear canal, a noisy testing environment, or the baby being restless during the screening. If the baby receives a “Refer” result, the initial test is often repeated within a short time frame, usually before the baby leaves the hospital or within two weeks of discharge.
If the baby refers on the repeat screening, the next action is a referral for a comprehensive diagnostic audiology assessment with a pediatric audiologist. This evaluation should be scheduled as soon as possible, ideally by the time the baby is three months old. The audiologist will perform a series of tests to determine the type, degree, and configuration of any potential hearing loss. If a permanent hearing loss is confirmed, the goal is for the baby to begin early intervention services no later than six months of age to support the best possible communication outcomes.