A hearing screening is a quick, non-diagnostic procedure designed to identify individuals who may have hearing loss. Its primary purpose is the early detection of potential auditory issues across all age groups. A screening does not determine the type or degree of hearing impairment. Instead, it indicates whether a full diagnostic evaluation is necessary, ensuring those with possible hearing challenges are referred for comprehensive testing and timely intervention.
Screening Procedures for Newborns and Infants
Screening for newborns and young infants requires objective methods because they cannot cooperate or respond intentionally. The two primary, non-invasive tests used are Otoacoustic Emissions (OAE) and Automated Auditory Brainstem Response (AABR). These tests provide information on the physical response of the auditory system rather than relying on a behavioral response.
Otoacoustic Emissions (OAE) testing evaluates the function of the cochlea, specifically the outer hair cells. A small, soft probe containing a microphone and speaker is placed gently into the infant’s ear canal. The speaker emits a quiet sound, and if the inner ear is working normally, the outer hair cells produce a faint “echo” that the microphone measures. A successful test result, or “pass,” means these emissions were recorded, suggesting the inner ear is responding appropriately to sound.
The Automated Auditory Brainstem Response (AABR) test measures the brain’s electrical activity in response to sound, checking the entire auditory pathway up to the brainstem. Three small electrodes are placed on the infant’s head, and sound is delivered through a small earphone or probe. The AABR device automatically analyzes the resulting brain wave patterns. AABR is often used as a secondary screening if the OAE test is inconclusive or for infants with risk factors for hearing loss, as it provides a broader check of the auditory nerve and brainstem function.
Screening Procedures for Older Children and Adults
For individuals who can follow instructions and cooperate, screening methods rely on their ability to perceive and respond to sound. These behavioral tests are adjusted based on the person’s developmental age and cooperation level. They use subjective, voluntary responses rather than the objective physiological measurements used for infants.
Pure-Tone Screening, also known as standard audiometry, is the most common method for school-age children and adults. The person sits in a quiet environment, wears headphones, and is instructed to signal—by raising a hand or pressing a button—whenever they hear a faint tone. The screener presents pure tones at specific frequencies (pitches) and a fixed, quiet intensity. This intensity is typically 20 decibels (dB) for children or 25 dB for adults, which are considered the upper limits of normal hearing. This assessment checks if the person’s hearing thresholds fall within the normal range for sounds important for speech comprehension.
Visual Reinforcement Audiometry (VRA)
For toddlers between six months and two and a half years old, Visual Reinforcement Audiometry (VRA) is used. The child is conditioned to turn their head toward a sound source. When they respond correctly, they are rewarded with an engaging visual stimulus, such as an illuminated toy or a brief video clip.
Conditioned Play Audiometry (CPA)
As children mature, typically between two and five years old, they transition to Conditioned Play Audiometry (CPA). Here, they are taught to perform a simple play activity, such as dropping a block into a bucket, every time they hear a tone.
Interpreting Screening Outcomes and Next Steps
The outcome of any hearing screening is typically reported as either “Pass” or “Refer.” A “Pass” indicates that the individual’s hearing mechanism responded within the expected limits for the test used. Conversely, a “Refer” result does not mean the person has a permanent hearing loss. It means they did not meet the established criteria for a pass during the screening.
A “Refer” result can occur for various reasons unrelated to a permanent hearing issue, such as fluid in the middle ear, temporary noise in the test environment, or the individual being uncooperative or moving excessively. Regardless of the potential cause, a “Refer” mandates a timely follow-up. The critical next step is a referral to a licensed audiologist for a comprehensive diagnostic evaluation.
This diagnostic assessment involves a battery of tests that are more detailed and frequency-specific than the initial screening. Timely follow-up is important, especially for infants, because early diagnosis and intervention—ideally by six months of age—are strongly associated with better speech and language development outcomes. The audiologist will pinpoint the exact nature, degree, and type of any hearing loss if one is present, allowing for the appropriate medical or rehabilitative treatment plan to be created.