We know that bats use sound to perceive objects in their surroundings, but people may also be able to use this skill.
Western University research is showing just how important it can be as a tool for people who are visually impaired.
Called echolocation, it can help the visually impaired to get around.
"Some blind people have learned how to make a mouth click, for example, then listen to the echoes from those mouth clicks returning back to them to locate objects and understand the world,” says Dr. Mel Goodale at Western's Brain and Mind Institute.
Previous Western research has shown that in blind people who echolocate, the information from these echoes is processed in an area of the brain responsible for vision.
The latest experiment involved what's called the size-weight illusion.
Researchers studied three groups: people who were sighted; those who were visually impaired and can echoloate; and visually impaired people who don't echoloate .
Each was asked to judge which was the heaviest box by pulling on a string attached to the different boxes.
"Clearly the blind people who don't echolocate had no idea what size the boxes were. When they pulled the string, all three boxes appeared the same weight because they had no idea how large they were,” Goodale says.
“I think it underscores once more that echolocation for people who are blind can (be used) as an effective aid to mobility."
