A Device for Human Ultrasonic Echolocation

Representing and interacting with the external world constitutes a major challenge for persons who are blind or visually impaired. Often, non-visual sensory modalities such as audition and somato-sensation acquire increased importance in sampling the environment. In many non-human species operating without vision, this is achieved by active echolocation, in which acoustic pulses are emitted and their reflections interpreted. The ultrasonic pulses employed by, e.g., bats and dolphins are highly informative but cannot be heard by humans. Here we present a device that combines principles of echolocation and spatial hearing to present users with environmental cues that are i) not otherwise available to the human auditory system and ii) richer in object and spatial information than similar systems employing extensive processing of echo information.