Listen closely: Prosodic signals in podcast support learning

Based on the assumptions of Cognitive Load Theory and its derived signaling principle, previous research on instructional material has mainly investigated the effect of including visual cues to support the processing and integration of information. In the context of the renewed interest in commented videos and podcasts as instructional materials, the present study investigates the influence of prosodic signals on learning with digital media. An online experiment was conducted with 102 German students using an audio podcast as digital learning material. The audio recording was varied following the prosody of human language in terms of a 2 (volume: regular vs. higher) × 2 (pace: regular vs. slower) between-subject design to examine signaling key concepts. The results showed a positive effect of both prosodic cues manipulations (main effects) on learning outcomes and the most substantial impact when cumulated. This aligns with previous research on visual cues and thus extends findings on the signaling effect to the auditory modality. However, the picture is not so clear-cut. Indeed, higher learning outcome was also associated with higher mental effort and load with higher volume and no difference in effort but a lower load for a slower pace. Further, the presence of signals was also paired with an underestimation of learning. Overall, this could indicate a difficulty in processing the prosodic cues and integrating the signaled elements in the mental model, with an unknown effect on longer-term learning. Future research could further investigate additional possibilities of prosody (e.g., neutral vs. euphoric tone) as prosodic cues and characteristics linked to the speaker (e.g., age, gender) in podcasts and multimedia documents.