Seeing by Sound

Researchers at Georgia Institute of Technology have come up with a solution to help the visually impaired navigate a city by transforming a cityscape into sounds. Most of the solution resides in a wearable backpack, and includes a laptop computer, two GPS receivers, head and body compasses, a gyroscope tracker to measure head tilt, four small digital cameras and a bone phone audio device that transmits sound by vibrating against a user's skull, leaving their ears free to take in sounds from the city. In total, it all weighs in at three pounds.

The system works by using the GPS device and cameras to place a user's location on a map. The user verbally tells the system their desired destination, and the system generates soft tones through the bone phones to navigate the user. While the system works fairly well for locations that have been mapped via GPS, it does have a little difficulty when the GPS signals fade -- such as between or in buildings. For those tricky spots, the system uses the cameras to locate the user on stored maps -- that means to be effective in buildings for instance, the building would have to be mapped.

The researchers are currently working on scaling the system down to have the cameras mounted on sunglasses and the computing reduced to fit on a PDA. For the visually impaired, this system promises a whole new level of freedom.