He actually did a TED talk two months ago at TED2015. It's from 4 years after the article above was written, and it's one of those talks that leaves you with li

He actually did a TED talk two months ago at TED2015. It's from 4 years after the article above was written, and it's one of those talks that leaves you with lingering thoughts for days afterward. https://www.ted.com/talks/daniel_kish_how_i_use_sonar_to_navigate_the_world?language=en https://www.ted.com/talks/daniel_kish_how_i_use_sonar_to_nav...