Abstract We describe a prototype of a navigation aid for the visually impaired. Our plans are for a portable, self-contained system that will indicate the positions of environmental landmarks to a blind traveler by having their labels, spoken by speech synthesizer, appear as virtual sounds at the correct locations within the auditory space of the traveler.
Vision serves several functions for human travelers.
A primary function is in connection with geographic orientation. Before setting out, the traveler may consult a map for determining an optimal route. Once underway, the traveler uses vision to sense distant landmarks for maintaining goal orientation and to sense nearer landmarks that signify a familiar route or that can be compared with those depicted in the map. Vision also provides access to optical flow for velocity-based dead reckoning. A second primary function is in connection with the local aspects of wayfinding, such as keeping the observer on the selected path, detecting hazards such as dropoffs, and avoiding stationary and moving obstacles.