Voice Volume Gauge to Encourage Vocal Adaptation of an Operator of a Teleoperated Social Robot

Teleoperated social robots have been widely studied and employed, yet their operation interfaces provide limited information to the operator, causing difficulties in grasping the dialogue situation compared to face-to-face interactions. Particularly with conventional interfaces, operators face challenges with vocal adaptation due to the inability to assess the distance between the robot and the interlocutor. Consequently, operators struggle to determine the appropriate volume level for clear communication, leading to insecurity about their vocalization’s effectiveness. In this study, we propose a novel approach to address this issue: a voice volume gauge that enables operators to adjust their voice volume by displaying the difference between their current volume and the estimated optimal volume on the interface. We implemented the gauge and conducted a subjective evaluation experiment, which demonstrated no usability concerns for operators and a reduction in their insecurity levels. Furthermore, preliminary objective evaluation results based on speech analysis suggest that utilizing the gauge may bring operators’ vocalizations closer to those in face-to-face dialogues. The contribution of this paper lies in providing a simple interface design method to aid in solving the vocal adaptation problem for teleoperated robot applications.