Abstract
Prior conducted research revealed that the auditory icons could contribute in supporting the virtual lecturers in presence of full body animation while delivering the learning content in e-learning interfaces. This paper presents further empirical investigation into the use of these supportive auditory icons by comparing three different e-learning interfaces in terms of usability aspects; effectiveness, user satisfaction and memorability. The aim is to find out which combination of the tested multimodal metaphors is the best one in terms of utilizing the auditory icons to supplement the presentation of learning material by virtual lecturer. The first experimental e-learning interface incorporates a speaking virtual lecturer with full body gestures along with supportive auditory icons. The second experimental e-learning interface includes the use of virtual lecturer speech in the absence of his body and accompanied with the same auditory icons used in the first interface. However, the third interface is similar to the second one in terms of using the virtual lecturer's speech but without any additional auditory icons. The obtained results have shown that the inclusion of auditory icons could enhance the usability and learning performance of e-learning interfaces much better if combined along with speaking virtual lectures in the absence of any body animation.