The efficacy of mass programs for testing the hearing of newborn infants still in the nursery is extremely controversial. This is primarily due to indequate analysis of stimulus and response variables, and a lack of definitive information gleaned from long-term follow-up studies on all children tested. The paper describes a unique project at the University of Nebraska in which 10 000 children tested for hearing loss in the nursery were subjects in a longitudianal study attempting to resolve questions regarding the prevalence of hearing disorders, the extent of false positive and false negative responses in the nursery, differential response patterns, and other sequelae. Substudies involving stimuli and response types, and the use of preconditioning auditory alerting signals are discussed. Lack of response to auditory stimuli when hearing is normal, response only to broad-band white noise, lack of response decrement, and the hyperactive response are considered, and some of the long-range implications of these forms of behavior are reviewed