New blind mobility aid devices based on the ultrasonic Doppler effect

An original approach to electronic blind mobility aid combined with ultraso nic wave processing and spatial hearing has allowed the design of new blind mobility aid devices. These devices convert inaudible ultrasound echoes in to audible sound via the Doppler effect, preserving even slight modificatio n 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 sp atial location.