An improved assistive technology system for the blind that uses sonification (visualization using sounds) has been developed byUniversidad Carlos III de Madrid (UC3M) researchers, with the goal of replacing costly, bulky current systems.
How it works: Called Assistive Technology for Autonomous Displacement (ATAD), the system includes a stereo vision processor measures the difference of images captured by two cameras that are placed slightly apart (for image depth data) and calculates the distance to each point in the scene.
Then it transmits the information to the user by means of a sound code that gives information regarding the position and distance to the different obstacles, using a small audio stereo amplifier and bone-conduction headphones.
“To represent height, the synthesizer emits up to eight different tones,” said co-developer Pablo Revuelta Sanz, who described the system in a doctoral thesis. In addition, the sounds are laterally located, so that something on the left sounds louder on that side, and vice versa.
Six profiles, ranging from one that is very simple, with a sound alarm that only works when one is going to crash into an obstacle, to others that describe the scene with 64 simultaneous sounds can be chosen.”
The prototype system was tested on 28 individuals, including sighted individuals, persons with limited vision, and blind persons. The final system was tested on eight blind persons in real environments.
According to Revuelta, “the aim of the system is to complement a cane or a guide dog, and not in any way replace them.” The estimated price of 250 euros is “very economical compared with other systems that are currently on the market.”