Persuasion and social perception of human vs. synthetic voice across person as source and computer as source conditions

There is evidence that people react more positively when they are presented with faces that are consistent with their voices. Nass and Brave [2005]. Wired for speech: How voice Activates and Advances the Human–computer Relationship. MIT Press, Cambridge, MA] found that computerized and human faces were perceived more positively when paired, respectively, with synthesized versus human voices than when paired with inconsistent voices. The present study sought to examine whether this type of inconsistency would effect perceptions of persuasive messages delivered by humans versus computers. We created a situation in which reactions to computer synthesized speech were compared to human speech when the speech was either from a person or a computer. This paper presents two studies, one using audio taped stimuli and one using videotaped stimuli, with type of speech (human versus computer synthesized) manipulated factorially with source (person versus computer). As hypothesized, both studies suggest that in the human as source condition, human voice is perceived more favorably than synthetic voice. However, in the computer as source condition, both human and computer voice were rated similarly. We discuss these findings in terms of consistency as well as group processes effects that may be occurring.