The comparative study described in this paper has been conducted to investigate the effect of including multimodal metaphors on the usability of e-learning interfaces. Two independent groups of users were involved to evaluate two different interfaces of an experimental e-learning platform. The control group used the visual only interface that presents information about class diagram notation in textual approach, and the experimental group used the multimodal interface in which a combination of recorded speech sounds, non-speech sounds (earcons), and avatar with simple facial expressions were employed to communicate the same information. Three usability parameters which are efficiency, effectiveness, and users’ satisfaction were considered in the study. The scope of this paper is to discuss the results that related to efficiency only, which has been measured by task completion time. It was found that the multimodal interface group taken significantly less time to complete the experimental tasks compared to the visual only interface group. These results encouraged for further exploration to examine the contributing role of each of the applied multimodal metaphors.