Echolocation refers to receiving information about surroundings by bouncing sound waves off surfaces. As for example, bats use echolocation to navigate and find food in the dark. There are two types of echolocation: passive echolocation and active echolocation. Passive echolocation can be used when sounds emitted by a source other than yourself. This type of echolocation occurs for humans every day. The other type of echolocation is active echolocation. This type involves emitting one's own sounds for echolocation, which can help perceive impressive detail. With that being said, passive echolocation occurs much more frequently for humans with all of the many sounds around us.