This study examines an aspect of the role of emotion in multimedia learning, i.e., whether participants can recognize the instructor's positive or negative emotion based on hearing short clips involving only the instructor's voice just as well as also seeing an embodied onscreen agent. Participants viewed 16 short video clips from a statistics lecture in which an animated instructor, conveying a happy, content, frustrated, or bored emotion, stands next to a slide as she lectures (agent present) or uses only her voice (agent absent). For each clip, participants rated the instructor on five-point scales for how happy, content, frustrated, and bored the instructor seemed. First, for happy, content, and bored instructors, participants were just as accurate in rating emotional tone based on voice only as with voice plus onscreen agent. This supports the "voice hypothesis," which posits that voice is a powerful source of social-emotional information. Second, participants rated happy and content instructors higher on happy and content scales and rated frustrated and bored instructors higher on frustrated and bored scales. This supports the "positivity hypothesis," which posits that people are particularly sensitive to the positive or negative tone of multimedia instructional messages.