  Bats use a sophisticated ultrasonic sensing method called echolocation to
recognize the environment. Recently, it has been reported that sighted human
participants with no prior experience in echolocation can improve their ability
to perceive the spatial layout of various environments through training to
listen to echoes (Norman, et al., 2021). In this study, we developed the new
training system for human echolocation using the eye-tracker. Binaural echoes
of consecutive downward linear FM pulses that were inspired by feeding
strategies of echolocating bats were simulated using the wave equation finite
difference time domain method. The virtual echoes were presented to the sighted
subject in response to his or her eye movements on the monitor. The latency
from eye gazing to the echo presentation wasn't audible delay to perceive. In a
preliminary experiment in which the participants were asked to identify the
shapes of the hidden target, the participants were found to concentrate their
gaze on the edges of the hidden target on the monitor. We will conduct a
psycho-acoustical experiment to examine the learning process of human
echolocation in a shape-identification task, which will lead to device
development in the field of welfare engineering.
