When Do Teachers' Pleasant Expressions in Video Lectures Facilitate Learning? The Role of Emotional Learning Materials and Auditory Emotions

Background Emotional cues in video lectures have demonstrated complex effects on learning, particularly regarding teachers' facial expressions. However, these effects remain inconclusive, necessitating further exploration of potential factors to enhance learning. Objectives This study examined how three forms of emotional design—learning materials, teachers' facial expressions and teachers' auditory emotions, individually and jointly influence learners' emotional responses, cognitive processing and learning outcomes in video‐based instruction. Methods Across two experiments, we investigated the independent and interactive effects of teachers' facial expressions, the emotional design of learning materials and teachers' auditory emotion on students' emotions, motivation, attention, cognitive load and learning outcomes. Experiment 1 examined the interaction between teachers' facial expressions and emotionally designed learning materials, while Experiment 2 built on these findings to test whether congruent positive facial and auditory cues further enhance students' emotional, motivational and cognitive engagement. Results In Experiment 1, when learning materials were neutrally designed, teachers' pleasant facial expressions reduced extraneous cognitive load and improved learning outcomes. Experiment 2 showed that pairing pleasant facial expressions with pleasant auditory emotion elicited more positive emotions, higher motivation, increased germane load and better learning outcomes. Eye‐tracking analyses indicated that this emotional congruence decreased attentional distraction, highlighting the synergistic benefits of combining visual and auditory emotional cues. Conclusions The study identifies the synergistic effects of various emotional design elements in video lectures on students' learning and contributes to theories of emotional design and cognitive processing in multimedia learning contexts. It also offers practical insights for educators on optimising emotional cues in video‐based learning environments.