Does Talking to a Robot in a High-Pitched Voice Create a Good Impression of the Robot?

When talking to infants, we tend to use infant-directed speech (IDS) rather than adult-directed speech (ADS). IDS attracts more attention from infants, conveys the emotions of adults more easily, and makes language acquisition easier. It is not clear, however, whether IDS has a cognitive effect on adults as well. To address this issue, we focus on one of the most distinctive features of IDS, a high-pitched voice. In addition, we conduct two human-robot interaction experiments to examine the following two hypotheses: (i) a robot reacting selectively to a high-pitched voice triggers a high-pitched voice of the user (H1), and (ii) talking to a robot in a high-pitched voice improves the user´s impression of the robot (H2). The results did not support H1, but marginally supported H2.