Exploring Verbal Uncanny Valley Effects with Vague Language in Computer Speech

Interactions with speech interfaces are growing, helped by the advent of intelligent personal assistants like Amazon Alexa and Google Assistant. This software is utilised in hardware such as smart home devices (e.g. Amazon Echo and Google Home), smartphones and vehicles. Given the unprecedented level of spoken interactions with machines, it is important we understand what is considered appropriate, desirable and attractive computer speech. Previous research has suggested that the overuse of humanlike voices in limited-communication devices can induce uncanny valley effects—a perceptual tension arising from mismatched stimuli causing incongruence between users’ expectations of a system and its actual capabilities. This chapter explores the possibility of verbal uncanny valley effects in computer speech by utilising the interpersonal linguistic strategies of politeness, relational work and vague language. This work highlights that using these strategies can create perceptual tension and negative experiences due to the conflicting stimuli of computer speech and ‘humanlike’ language. This tension can be somewhat moderated with more humanlike than robotic voices, though not alleviated completely. Considerations for the design of computer speech and subsequent future research directions are discussed.