Researchers at the University of Bristol have designed a helmet that guides visually impaired walkers through the use of sound. Using technology developed at the University of Laguna in Spain, imagery captured of objects such as trees, people, and furniture are converted to sound. The result is an acoustic map that allows blind people to navigate around objects both stationary and moving. The resulting sounds get louder as the person nears the object and quieter as the person moves away. The location of objects is conveyed by hearing the sound on the side of the head where the object is. Imminent collisions are forewarned through an urgent tone.
The first design (M1) uses a laser sensor developed by Siemens and originally intended to detect passengers in cars. It can calculate the distance to objects within 0 to 5m in a 60º field of view. The system is mounted inside glasses and cannot be seen by others because it uses infrared light. The M1 has been extensively tested by blind users who are able to recognise items, such as chairs and trees, from the sound picture they receive.
A second version (M2) adds two digital video cameras to either side of a helmet. It can detect moving objects and predict their path.
Future prototypes involved integrating GPS to help provide directions to the walker.