Hearing impairment in the developing child can have far reaching and long lasting consequences. In addition to communicative difficulties, children with undetected or misdiagnosed hearing impairment can suffer intellectually, socially, emotionally and/or behaviorally. There is little reason, however, for infants or children with hearing impairment to go without accurate assessment because the pediatric audiologist is now armed with reliable test techniques for virtually every child. This paper is a review of some of the behavioral and physiological methods used by the audiologist to identify and describe the hearing of infants and children. Also included are suggestions for the pediatrician about when it is appropriate to request the help of the audiologist in evaluating an infant or child at risk for or with suspected hearing loss.