Citation: Morita, T.; Zhu, Y.; Aoyama,
T.; Takeuchi, M.; Yamamoto, K.;
Hasegawa, Y. Auditory Feedback for
Enhanced Sense of Agency in Shared
Control. Sensors 2022, 22, 9779.
https://doi.org/10.3390/s22249779
Academic Editors: Hamed Rahimi
Nohooji and Abolfazl Zaraki
Received: 13 October 2022
Accepted: 10 December 2022
Published: 13 December 2022
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Article
Auditory Feedback for Enhanced Sense of Agency in
Shared Control
Tomoya Morita
1,
* , Yaonan Zhu
1
, Tadayoshi Aoyama
1
, Masaru Takeuchi
1
, Kento Yamamoto
1
and Yasuhisa Hasegawa
1
Department of Micro-Nano Mechanical Science and Engineering, Nagoya University, Nagoya 464-8601, Japan
* Correspondence: morita@robo.mein.nagoya-u.ac.jp
Abstract:
There is a growing need for robots that can be remotely controlled to perform tasks of
one’s own choice. However, the SoA (Sense of Agency: the sense of recognizing that the motion
of an observed object is caused by oneself) is reduced because the subject of the robot motion is
identified as external due to shared control. To address this issue, we aimed to suppress the decline
in SoA by presenting auditory feedback that aims to blur the distinction between self and others.
We performed the tracking task in a virtual environment under four different auditory feedback
conditions, with varying levels of automation to manipulate the virtual robot gripper. Experimental
results showed that the proposed auditory feedback suppressed the decrease in the SoA at a medium
level of automation. It is suggested that our proposed auditory feedback could blur the distinction
between self and others, and that the operator attributes the subject of the motion of the manipulated
object to himself.
Keywords: robotic teleoperation; sense of agency; auditory feedback
1. Introduction
For many years, research has been conducted on operational robots that work remotely
in place of humans in extreme environments such as nuclear power plants, undersea, and
at fire scenes [
1
]. In recent years, there has been a growing need for robots that can be
operated remotely, such as by blue-collar teleworkers. In robotic teleoperation, a sense
of immersion in the workspace and operability are major factors that contribute to the
achievement of aims. Our research group have developed an intuitive system that enables
immersive and intuitive robot teleoperation [
2
,
3
]. In this system, the position and posture
of the VR controller and those of the head-mounted display (HMD) worn by the operator
can be reflected on the arm and head of the remote robot, respectively, and parallax images
from the stereo camera mounted on the robot head are displayed on the HMD. This kind of
immersive robot teleoperation can be expected to further improve operability by promoting
robotic embodiment. Robotic embodiment is the illusion that the operator perceives the
robot arm or robot body as part of his or her own, which allows the operator to plan and
control the robot’s motion as if it were his or her own body [
4
–
11
]. One of the factors
that promote robotic embodiment is sense of agency (SoA). SoA refers to the sense of
recognizing that the motion of an observed object is caused by oneself [
12
], and it has been
attracting attention in the field of rehabilitation in recent years [13].
SoA decreases when the movement of the manipulated object differs from the opera-
tor’s intention. This can be explained by the comparator model, which has been proposed
as a mechanism for generating SoA [
12
,
14
,
15
]. SoA arises when the sensory feedback
predicted by the internal prediction model formed in a human brain matches the perceived
actual sensory feedback. Conversely, when the actual feedback differs from the intended
feedback, the SoA decreases. This decrease is expected to cause a decrease in motivation
for the task [16].
Sensors 2022, 22, 9779. https://doi.org/10.3390/s22249779 https://www.mdpi.com/journal/sensors
