How does auditory brainstem response testing measure hearing in infants?

Auditory brainstem response (ABR) testing is a clinical procedure used to estimate hearing sensitivity in infants, particularly when behavioral testing is not yet feasible or when initial screenings indicate potential issues.1

The test measures electrical potentials—brain activity produced in response to sound—using recording leads attached to the infant's scalp. Because the procedure can be performed while the infant is sleeping, it is the preferred method for pediatric assessment.1

During the test, the clinician typically begins by presenting sounds at a high intensity level and gradually reduces the volume until the evoked brain response can no longer be detected. The presence of a response is then determined based on the tester's subjective interpretation of the resulting waveform. If further evaluation is required, clinicians may also utilize auditory steady state response testing, which measures brain activity in response to tones of varying frequency and intensity, using statistical data to confirm the presence of a response.1