Not sure why he wouldn't use this, this seems vastly superior to the system he uses:
If you look at my other post, I linked to a video of a kid who used echolocation. He could distinguish objects - he walked past two garbage cans in the street, and said "Is that a car? clicks his tongue several times No, it's a garbage can."
I'd like to get his opinion of this: http://www.seeingwithsound.com/