Now, can we do the same thing with the human body? Theoretically? yes. Practically? no. The human body is way more complex, dense, and not at all uniform in static frequency than a piece of thin glass. Add to that that these conditions in the body change from moment to moment as we move and breathe, (especially if fighting) and also add to that the fact that it's impossible for the person "Kiai-ing" (even if he was a mathematical genius) to know all the precise frequencies from moment to moment of which to use, and at what duration to use them in (which would need to be quite long and powerful anyway, much more powerful than the human vocal cords can produce) and frankly, I know for a fact most of you all can out-Kiai this guy without much effort. ~and I haven't heard that any of you have been ringing any temple bells or knocking folks out with your Kiai lately.