'You, Move There!': Investigating the Impact of Feedback on Voice Control in Virtual Environments

Current virtual environment (VEs) input techniques often overlook speech as a useful control modality. Speech could improve interaction in multimodal VEs by enabling users to address objects, locations, and agents, yet research on how to design effective speech for VEs is limited. Our paper investigates the effect of agent feedback on speech VE experiences. Through a lab study, users commanded agents to navigate a VE, receiving either auditory, visual or behavioural feedback. Based on a post interaction semi-structured interview, we find that the type of feedback given by agents is critical to user experience. Specifically auditory mechanisms are preferred, allowing users to engage with other modalities seamlessly during interaction. Although command-like utterances were frequently used, it was perceived as contextually appropriate, ensuring users were understood. Many also found it difficult to discover speech-based functionality. Drawing on these, we discuss key challenges for designing speech input for VEs.