This study aimed to test the effectiveness of classroom translations of some laboratory procedures for teaching simple auditory discriminations to learners with developmental disabilities. Three participants with autism and mental retardation were trained to make topographically distinct responses in the presence of two different stimuli, either a pure tone and silence, or two tones. A portable electronic piano keyboard was used to produce tones. Delayed prompt and differential reinforcement procedures were used to teach the responses. None of the participants performed the discriminations accurately without prompting despite numerous revisions to the procedures.