New blind mobility aid devices based on the ultrasonic Doppler effect
Laurent Bitjoka, Léandre Pourcelot · International Journal of Rehabilitation Research · 1999
An original approach to electronic blind mobility aid combined with ultrasonic wave processing and spatial hearing has allowed the design of new blind mobility aid devices. These devices convert inaudible ultrasound echoes into audible sound via the Doppler effect, preserving even slight modification of the high frequency wave, so as to provide the user with higher acuity information regarding his movement, as well as object movement and their spatial location.