Do me a favor and try this: stay where you are and click your tongue against the roof of your mouth. Now walk somewhere else, and click your tongue again. Can you hear a difference? Congratulations, you’re on your way to learning how to echolocate! Whales and dolphins use echolocation to navigate and locate objects in the dark ocean. According to acoustic experts in Spain, people can use tongue clicks to “see” things by listening to the way the noise reverberates off its surroundings. All you have to do is recognize changes in your tongue clicks based on what is around you. Apparently, two hours per day for a couple of weeks is enough to determine if something is in front of you, and it takes a couple more weeks to differentiate between a tree and pavement. The most ideal sound is the “palate click” where you place the tip of your tongue on the roof of your mouth just behind your teeth and quickly move your tongue backwards. Most animals that use echolocation, including whales and dolphins, have specially-adapted organs that help to process these signals. Dolphins can generate up to two hundred clicks per second, while humans can only make three or four clicks. In addition, other animals don’t get the “cotton mouth” effect—the progressive dryness of the mouth. But humans are still learning from the animals: at least two blind people who have already taught themselves to echolocate have made the news. And scientists are working on teaching echolocation to people who work in dark and smoky conditions, like firefighters. Good luck -- And don’t forget to tell me how you do!