The impact of the physical and social embodiment of voice user interfaces on user distraction

•Comparing distraction in a cognitive task across voice-only, physical embodied, and social embodied voice user interfaces (VUI).•Social embodied VUI caused most distraction but was also most liked.•Voice-only VUI caused the least distraction but was also least liked.•Physical embodied system was overall preferred and received highest ratings in perceived calm, but caused some distraction. The concept of calm technology envisions that interaction with technology should consume minimal resources and cause as few distractions as possible. The main goal of our study was to compare different forms of embodiment of Voice User Interfaces (VUI) in terms of how much they distract a user from a cognitive task. We used a voice-only system without physical embodiment (voice-only), a physical embodied system without anthropomorphic features (physical embodied), and a social embodied VUI with social cues such as eye movements (social embodied). In addition, we explored the relationship between design features of the VUI and perceived distraction, social presence, and perceived calm. Twenty-four participants carried out four different cognitive tasks with the three different VUI and one round of cognitive tasks without any VUI present. The cognitive tasks were chosen from a serious game (BrainTagger Suit) and included measurements of cognitive speed, working memory, visual memory, and process inhibition. Overall, results indicated the voice-only VUI caused the least distraction, especially for cognitive speed, while slightly showing impairment for visual memory. Social embodied VUI appeared to cause the most distraction across the four cognitive tasks with physical embodied VUI falling in between. Surprisingly, social presence was perceived as highest for the voice-only system which at the same time received the lowest scores for perceived calm. The advantages and disadvantages of each VUI are discussed.