The PLATO Elementary Reading Curriculum (PERC) requires the use of two interactive PLATO terminals in each classroom, and each unit uses a random access audio device which is connected directly to the terminal. Messages from the command unit can direct the audio unit to deliver verbal instructions to the student user at the terminal. The PERC project has developed four simple guidelines for using audio in lessons: (1) keep messages as short as possible; (2) make cues easily identifiable; (3) allow students to interrupt the audio; and (4) provide minimal context to aid understanding. These guidelines have been found effective with six-year-olds. (EMH)