[nagdu] Ultrasonic mobility devices

[Tracy Carcione]

Has anyone used any of the sonic guides, those things that send out a beam
and vibrate when they find an obstacle?
I tried one many years ago, and found it a bit confusing, but I only had a
couple minutes to try it, and think experience would have made it more
clear.
I'm looking at an ad for the IGlasses ultrasonic guide for a pretty
reasonable price, if it's useful, but mostly I'm curious how useful it is.
I'd be real interested in any experiences anyone has had with these
things.  For instance, perhaps one could use it to "see" some bushes
coming up the dog might sniff, or to find a bench, when the dog is trying
to lead one around the bench--that kind of thing?
Tracy