A radar-based navigation assistance device with binaural sound interface for vision-impaired people

Abstract

Sound is extremely important to our daily navigation, while sometimes slightly underestimated relative to the simultaneous presence of the visual sense. Indeed, the spatial sense of sound can immediately identify the direction of danger far beyond the restricted sense of vision. The sound is then rapidly and unconsciously interpreted by assigning a meaning to it. In this paper, we therefore propose an assisted-living device that deliberately stimulates the sense of hearing in order to assist vision-impaired people in navigation and orientation tasks. The sense of vision in this framework is replaced with a sensing capability based on radar, and a comprehensive radar profile of the environment is translated into a dedicated sound representation, for instance, to indicate the distances and directions of obstacles. The concept thus resembles a bionic adaptation of the echolocation system of bats, which can provide successful navigation entirely in the dark. The process of translating radar data into sound in this context is termed ﾓsonificationﾔ. An advantage of radar sensing over optical cameras is the independence from environmental lighting conditions. Thus, the envisioned system can operate as a range extender of the conventional white cane. The paper technically reports the radar and binaural sound engine of our system and, specifically, describes the link between otherwise asynchronous radar circuitry and the binaural audio output to headphones.