What is the SD for a vocal echoic response?

The correct answer, which identifies the SD for a vocal echoic response as auditory, highlights the nature of echoic behavior in verbal operants. Echoics involve the repetition of what has been heard, making the auditory stimulus the direct antecedent that evokes the response. In this scenario, the individual listens to a spoken word or phrase and then echoes it, demonstrating the relationship between the sound they hear and the vocal response they produce.

The auditory stimulus serves as the discriminative stimulus (SD) because it triggers the echoic behavior. It's critical to understand that while both auditory and verbal components are involved—since echoics are a form of vocal behavior—the specific antecedent in this case is auditory. This distinction is essential in the context of verbal behavior analysis and understanding how different verbal operants are prompted and maintained within learning environments.