Intended as a method of increasing children's learning from commercial television by providing supplementary educational commentary on a simultaneous radio broadcast, this study was designed to explore the potential of dual audio instruction as a mass educational system by determining the medium's practicality, the rate of voluntary usage, the amount of material learned, the amount of verbal interaction due to dual audio, and the general reactions of parents, teachers, and children. A field experiment was conducted involving 872 inner-city first and second graders over a 2 month period. Results of the study indicated that it was possible to make and maintain all the necessary arrangements for broadcasting dual audio television, and that the dual audio supplement increased the television program's share of the available television audience. The use of viewer-owned FM radios was shown to be a feasible way of receiving dual audio instruction. (RB)