Little Voices, Big Impact: How Child‐Like Robot Voices Improve Service Quality

ABSTRACT Service robots play a critical role in shaping service delivery and influencing consumer behavior by enhancing operational efficiency, personalizing interactions, and creating unique service experiences. Drawing on the stimulus–organism–response (SOR) framework, this research investigates how robot vocal characteristics influence consumers' perceived service quality through functional and social‐relational values in a hedonic service context while examining the moderating role of consumers' need for social interaction. A preliminary text analysis and three experimental studies featuring a hotel reception robot (NAO) were conducted. Study 1 demonstrated that a child‐like (vs. adult) voice enhanced consumers' perceived service quality. Study 2 further revealed that this effect was mediated by both functional value and social‐relational value, with stronger perceptions elicited by the child‐like voice. Study 3 showed that consumers' need for social interaction positively moderated the indirect effect of a child‐like voice on perceived service quality through social‐relational value. In contrast, robot vocal gender (female vs. male) did not significantly influence perceived service quality. These findings highlight the importance of robot vocal age, demonstrating that age‐related vocal cues shape consumers' functional and social evaluations of service robots. The study extends the literature on human–robot interaction and provides practical guidance for designing robot voices that align with consumers' social needs to maximize service effectiveness.