Once the computer finds the user's target location, it maps a route and
transmits audio cues to headphones worn
behind the ears.
To the listener, the audio beacons sound as if they originate
from a few feet ahead. The person walks toward the beacon, which
can shift left or right to keep the user on course.
But because visually impaired people rely more heavily on sound, using
sound as a directional cue may not be the perfect solution.
"You still have the possibility that the sound will perceptually make
it hard to hear other sounds that you are trying to pick up from the
environment," said professor Jack Loomis of the University of
California, Santa Barbara, who has been investigating high-tech
navigation systems for the blind since 1985.
"Maybe future navigational systems should have options, such as
Braille, or speech, or spatial sound in earphones, or maybe
vibration," said Loomis.
Dellaert and Walker would like to give visually impaired people an
option that is inexpensive and lightweight. Currently they are working
to shrink the bulky prototype to a system that could be commercialized
in a cell-phone-sized package.
