Four-and-one-half- to eight-and-one-half-year-old children with normal language development, normal adults, and dysphasic children were tested for their ability to perceive binary sequences of nonverbal auditory stimuli. Performance was studied in relation to the rate of presentation of stimulus sequence, as measured by the time interval between stimulus elements. Of the normal children studied, only the eight-and-one-half-year-old group responded as well as the adult group to auditory patterns composed of complex tones presented in rapid succession (8-305 msec intervals). Normal children six-and-one-half years and older were able to respond to these same auditory patterns when they were presented more slowly (947-4026 msec intervals). The overall pattern of performance of the dysphasic children was not similar to that of any age group of children with normal language development. The dysphasics' performance was significantly poorer than that of even the four-and-one-half-year-old normal group on rapidly presented auditory sequences, but not significantly different from normal children their own age or adults on the same patterns which were presented more slowly. The interrelation of normal development of rapid auditory processing and normal language development is discussed.