Comment Human hearing is amazing (Score 4, Informative) 40
This is simply using our amazing ability to spatially locate sounds. We can spatially locate sounds in front of us side-to-side with an accuracy of around 1 degree. That's pretty incredible. For comparison, cats and dogs cannot spatially locate sounds with nearly that accuracy (about 5 degrees for cats, 8 degrees for dogs), even though they can physically pan their ears around to focus sound collection where they want.
To give an idea of just how incredible that is, 1 degree accuracy means that a sound (or echo) from 20 feet away can be determined with 4 inches accuracy side to side (or in metric, an object 6 meters away can be located to 11 centimeters accuracy).
Using this innate ability for echolocation just makes sense.