Sound localization in a median plane using an avatar robot "TeleHead" with synchronization of a listener's horizontal head rotation

Demands for realization of communications with a high sense of presence have become great. For such communications, it is important acoustically to capture and transmit comprehensive sound space information of remote places to a local site. The authors developed an avatar robot, which was developed as a simplified version of TeleHead proposed by Toshima et al. The robot's head moves synchronously, following the listener's horizontal head rotation. The authors investigated perceptual sound localization accuracy in the median plane at a remote site. Results show that sound localization accuracy is improved when the robot rotates synchronously with the listener's head rotation. Another sound localization test was conducted to examine the effects of manipulating the ratio of the rotation angle. The ratio between the listener's actual movement and that of the robot varied systematically. Results show that the ratios only slightly affect the accuracy of perceived elevation angles, suggesting large robustness in using cues provided by head rotation.