<p>Verbal behavior developmental theory (VBDT) has identified several pre-verbal developmental cusps related to learning and language acquisition. Adult faces as well as adult voices functioning as conditioned reinforcers are among the critical foundational cusps for early learners. The current study tested the effects of a synchronous reinforcement procedure on the acquisition of observing responses related to attending to adult and peer faces and adult voices for three preschool children with disabilities. We used a concurrent multiple probe design across participants with pre- and post-intervention measures for observing responses for adult and peer faces, observing responses to adult voices, and trials to criterion for instructional objectives. Following the procedure, all three participants showed increased observing and attending to adults and peers. In addition, this procedure led to improved learning outcomes, with a decrease in the number of trials to criterion for acquisition of objectives post-intervention. A notable observation was the increased attention to peers following the intervention, a phenomenon not previously investigated.</p>