A Novel Active Human Echolocation Device

Some animals, like bats and dolphins, can echolocate themselves and navigate through complete darkness. They can generate ultrasonic signals and locate themselves based on the echo bounced back from the surrounding objects/structures. As human, we lack such abilities to echolocate ourselves, and we mainly rely on our vision to guide and navigate. However, recently, some visually impaired people have trained and learned the skills to echo locate themselves demonstrating that we can too echo locate ourselves with our own hearing. Based on this principal, we propose a novel wearable device that can aid both sighted and visually impaired people in acquiring the echolocation skills. As our hearing is tuned to filter out echos, the proposed device is designed with an ultrasound transmitter with a carrier frequency of 40 kHz and modulated with a signal with 2kHz frequency to generate a click sound that could be heard by the user for echolocation. Hence, the brain experienced far less confusion while attempting to comprehend the surrounding world and isolate the aspects necessary to acquire the abilities. To assess the ability of user to acquiring the echolocation skills, a healthy subject study was conducted where six training sessions that we conducted, and EEG (electroencephalogram) signal of the subjects were collected while they were blindfolded and using the proposed device to echolocate. From the results, we have shown that there was a significant correlation between their echolocation training and the intensified activations of the visual cortex area demonstrating the subjects were able to use the echoed signal to ’visualize’ the surrounding environment. It also shows the subjects’ ability to learn and echolocate themselves quickly in a room fitted with a random objects.