The Blind Man Who Taught Himself To See
“There are two reasons echolocation works. The first is that our ears, conveniently, are located on both sides of our head. When there’s a noise off to one side, the sound reaches the closer ear about a millisecond — a thousandth of a second — before it reaches the farther ear. That’s enough of a gap for the auditory cortex of our brain to process the information.”
An absolutely fantastic story of a man that overcomes his lack of sight by mastering echolocation.