“Two hours per day for a couple of weeks are enough to distinguish whether you have an object in front of you,”
says lead researcher Juan Antonio Martinez, from the University of Alcalá de Henares in Spain. “Within another couple weeks you can tell the difference between trees and pavement.”
Reported in Australian CSIRO Science mail (10th July 2009) Dolphins and bats have a way of detecting objects by using sound instead of sight. They make a sound and listen to the echo as it returns from different objects. This process is called echolocation. Scientists have discovered that with just a few hours of training, humans can start to echolocate too.
Dolphins make a clicking sound to echolocate. It is recommended that humans use a click also. This click is made by placing the tip of the tongue on the palate, just behind the teeth, and moving it quickly backwards.
“The palate click is better than other sounds, because it can be made in a uniform way, works at a lower intensity, and doesn’t get drowned out by ambient noise,” says Juan.
The more clicks you can make and the higher the pitch, the more you can ‘see’. Humans can only produce 3-4 clicks per second, while dolphins can make up to 200. Humans also face the challenge of a dry mouth, as it causes the quality of sound to decrease after a few minutes of constant performance.
In the future, this research may have many applications, such as helping the blind to echolocate without the use of technology. It would require no additional devices and they would not be reliant on batteries or electronics.
Want to give it a go? Juan recommends starting with a ‘sh’ sound, the type you would use to ask someone to be quiet. Listen carefully as you move a pen in front of your mouth – you will start to hear the difference!