We tested the effects of the establishment of conditioned reinforcement for observing human faces and/or voices on the rate of learning, observing responses, and verbal operant emissions for four children, ages 4-5 years, with autism spectrum disorders (ASD) and related disorders. We used a non-concurrent, delayed probe design across participants with pre and post-intervention measures. The intervention included a conjugate stimulus-stimulus pairing procedure. Results demonstrated that as a function of the intervention, faces were conditioned for three out of three participants and voices were conditioned for two out of two participants for whom either was lacking respectively prior to the intervention (both faces and voices were conditioned for one participant). Post-intervention probes demonstrated increases in rate of learning, observing responses, and verbal operants for all four participants.