The search for better means of testing for antepartum fetal well-being is a major objective of perinatal medicine. This preliminary report explores the use of a 2,000 c.p.s. pure-tone auditory stimulus for "nonstress" testing, a comparison with the oxytocin challenge test (OCT), and a correlation with fetal outcome. Instead of waiting, when the fetus may be inactive or "sleeping," for a positive fetal heart (FHR) response following a fetal kick or movement, a rapid "nonstress" test may be performed by evoking an FHR acceleration after the application of a five-second auditory stimulation at 105 to 120 db. When FHR acceleration evoked exceeded 15 b.p.m., the subsequent OCT was always negative. Suspicious or positive OCT's were frequently obtained when no response to auditory stimuli occurred. Subsequent outcomes as well as safety and potential applications of this rapid test which may eliminate the need for many OCT's are discussed.