A coherence effect in multimedia learning: The case for minimizing irrelevant sounds in the design of multimedia instructional messages.

The authors tested the recommendation that adding bells and whistles (in the form of background music and/or sounds) would improve the quality of a multimedia instructional message. In 2 studies, students received an animation and concurrent narration intended to explain the formation of lightning (Experiment 1) or the operation of hydraulic braking systems (Experiment 2), For some students, the aathors added background music (Group NM), sounds (Group NS), bom (Group NSM), or neither (Group N). On tests of retention and transfer, Group NSM performed worse than Group N; groups receiving music performed worse than groups not receiving music; and groups receiving sounds performed worse (only in Experiment 2) man groups not receiving sounds. Results were consistent with the idea that auditory adjuncts can overload the learner's auditory working memory, as predicted by a cognitive theory of multimedia learning. Humans are designed to integrate multimodal stimuli into one meaningful experience, such as when they associate the sound of thunder to the visual image of lightning in the sky. However, when the process of lightning formation is to be taught using a computer, the instructional designer is faced with the need to choose between several alternative presentation formats to promote meaningful learning (Mayer & Moreno, 1998). Within the visual modality, for example, the process of lightning may be shown by a static diagram, an animation, or a video, and it may be described by visually presented text. Within the auditory modality, for example, the process of lightning may be accompanied by sound effects or background music, and it may be described by an auditorily presented narration. The present study examines one aspect of multimedia design, the role of auditory adjuncts such as background music and sound.