Newborn hearing screening is an electrophysiologic test to determine whether a newborn’s hearing is impaired. Newborn hearing screening is usually best performed while the baby is naturally sleeping, and is a preliminary screening test to determine if the newborn’s auditory system is developing normally. When the newborn hearing screening results show an abnormality, it is not certain that the child has a hearing problem, and further testing is needed to confirm whether the child has a hearing impairment. Because newborns in their first 1-3 days of life have more oily secretions in the external ear canal and amniotic fluid in the middle ear cavity, which may interfere with the results and make it easy for false positives to occur, newborn hearing screening is usually performed 3-5 days after birth. If the test result is abnormal, it is recommended to review the test or go to a specialized hospital.