Measurement of hearing acuity in newborn infants is important for early detection of auditory disorders and establishment of rehabilitation. In 1873, Genzmer reported that the newborn infants began to response to a sound stimuli within two days after birth and found a clearcut blinking response, auropalpebral reflex, evoked by auditory stimulation with a striking bell. Since then many inverstigators engaged in the study of hearing tests in newborn infants attempting to reduce the incidence of deafness in newborn infants. There are various methods of audiologic tests for newborn infants, which can be divided into two categories ; an subjective method such as observation of behavior response evoked by sound stimulation and an objective one such as ERA and Crib-O-Gram. Although ERA and observation of heart rate changes are popular as a reliable objective method, it can not be applied as a screening test for its time taking procedure. Authors had a screening test with Warblet tone audiometer to 100 newborn infants who were born in Severance hospital and the results are as follows ; 1) 34 out of 100 cases showed negative or questionable response. 2) Response rate according to infant's condition was highest in light sleep (85%) and lowest in deep sleep (20%). 3) The most common reflex was auropalpebral (29%) and then ceasing of activity, startle, eye shift or widening, crying in descending orders. 4) Response rate was higher in infants over 4 day-old (77%) than in infants under 1 day-old (42%).