Image by vinduhl via FlickrI was echolocating through the hallway at work the other day, and I noticed a lot of high frequency noise which I think has been there all along, but I hadn't really paid attention to it. I think it was either coming from the deformation of the carpet fibers under my feet, or the stretching of the fabric in my shoes because it was synchronized with my gait. It wasn't necessarily just the sound of footsteps, because it seemed like it was always present, and just increased in volume at every step.
After listening to this sound for a while I realized that I was actually using it quite effectively to echolocate. Possibly more effectively than clicking. And I can see where the myth of "pressure on the face" comes from. Since this sound was more omnipresent than the sporatic clicking you get a much better transition between the "presence" of different objects.
This makes me wonder, if some white noise were to be emitted at, say, the belt buckle level (somewhere away from the ears, but a source that travels with you) if that would be of great benefit for echolocation. Maybe clicking is not the way to go?
Anyone out there ever notice this phenomenon? Let me know what you think.