The objectives of this study were to determine: (1) the variables that influence the learning of verbal material received by subjects via the aural modality, (2) how learning under conditions of aural reception compare with learning of the same materials under appropriately equivalent visual conditions, and (3) in what combinations learning is affected by variously combined joint audio and visual presentation. Variables selected for consideration, in addition to reception mode, were meaningfulness, abstractness, and similarity. Subjects were undergraduate males and females at the University of Iowa, assigned randomly to treatments. The results of the 17 experiments conducted indicated: (1) with few exceptions, the same laws operate on the learning of verbal materials under both aural and visual conditions of reception, (2) a variable affecting visual learning will probably also affect aural learning, (3) sexual differences do not appear with respect to mode of input, and (4) it would appear that differences of performance as a function of input mode noted in this research are not to be viewed as having deep practical consequences for classroom learning. Tables are included. (Author/CJ)