Last week, when I was on vacation with my family, we were sitting on the deck when a bat flew extremely close to us. After being quite startled and screaming a little, my sister started to tell us about humans who are capable of echolocation. She explained that some humans who are blind can use a clicking noise that they make with their tongue to locate objects and understand their surroundings. Fascinated by this, I did a little research, and it’s true! There’s such a thing as human echolocation, also known as flash sonar.
Humans who can see and hear gather information about their environment based on visual and auditory input. Both types of input come in the form of waves: light waves and sound waves. However, blind individuals using flash sonar depend solely on the sound waves, otherwise known as echoes. The clicking noises that blind individuals make are sound waves (or echoes) that bounce off of objects in the environment. Depending upon how the sound waves hit the objects and bounce back to the individual, the echoes provide the individual with lots of information about the surrounding objects, for example the distance to an object, the size and density of an object, and the exact location of an object. Some individuals, like Daniel Kish, are so talented at flash sonar that they can cross an intersection and ride a bike. In fact, Daniel trains young blind children to use flash sonar.
Check out this video of Daniel. Some people refer to him as a human batman!
It’s so interesting that two different systems in the brain can provide the same information but with very different types of input!