According to Cognitive Load Theory and Perceptual Load Theory, different types of loads are generated through auditory and video stimuli. Because auditory and visual modalities, and the nature of their loads differ, one may ask if this difference has implications for online learning. Specifically, in online learning, could some lectures be held as auditory podcasts instead of audio + video. Should the teaching switch between auditory-only and video-only formats? Can these questions be answered with limited resources, using inexpensive behavioural experiments? Sixteen participants were presented with either the audio + video or audio-only tasks, with questionnaires on comprehension and cognitive load following each task. Results showed no decrease in learning outcomes from audio-only and audio + video tasks, challenging the notion that multimodal inputs always increase cognitive load. Contrary to expectations, participants reported that audio-only tasks required more mental effort, which might be due to individual preferences for visual learning. The study's findings indicate that factors beyond cognitive load, such as perceptual load and individual learner characteristics, should be considered to optimise learning environments. The study highlights the importance of managing cognitive and perceptual loads associated with learning tasks.