International Journal of Social Robotics

, Volume 5, Issue 2, pp 171–191 | Cite as

Making Social Robots More Attractive: The Effects of Voice Pitch, Humor and Empathy

  • Andreea NiculescuEmail author
  • Betsy van Dijk
  • Anton Nijholt
  • Haizhou Li
  • Swee Lan See


In this paper we explore how simple auditory/verbal features of the spoken language, such as voice characteristics (pitch) and language cues (empathy/humor expression) influence the quality of interaction with a social robot receptionist. For our experiment two robot characters were created: Olivia, the more extrovert, exuberant, and humorous robot with a higher voice pitch and Cynthia, the more introvert, calmer and more serious robot with a lower voice pitch. Our results showed that the voice pitch seemed to have a strong influence on the way users rated the overall interaction quality, as well as the robot’s appeal and overall enjoyment. Further, the humor appeared to improve the users’ perception of task enjoyment, robot personality and speaking style while the empathy showed effects on the way users evaluated the robot’s receptive behavior and the interaction ease. With our study, we would like to stress in particular the importance of voice pitch in human robot interaction and to encourage further research on this topic.


Social robots Voice pitch Humor Empathy User studies Quantitative evaluation 



We are grateful to A*STAR Robotics team for their excellent development work on Olivia 4.0 service-robot model. Special thanks to Adrian Tay and Han Boon Siew for their constant help during the experiment, and to Tan Yeow Kee and Brian Ho for acting as wizards during the experiment. We are also grateful to Lynn Packwood for careful proof reading. This work has been supported by the EU’s 7th Framework Program (FP7-ICT-2011.2.1) under grant agreement No. 288235 (FROG).


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Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • Andreea Niculescu
    • 1
    Email author
  • Betsy van Dijk
    • 1
  • Anton Nijholt
    • 1
  • Haizhou Li
    • 2
  • Swee Lan See
    • 2
  1. 1.Human Media InteractionUniversity of TwenteEnschedeThe Netherlands
  2. 2.Institute for Infocomm ResearchSingaporeSingapore

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