WBFA– Now, I'll have to admit that my M Theory is a bit hazy, but as far as I understand it, if another brane were to intersect with our own, the effects would be… noticeable. Like, another Big Bang kind of noticeable. Other than that, my basic understanding is that parallel universes can't communicate in any way with ours. I like it in that it's a scientific hypothesis, though, and we may someday find out an answer.
Jim– as far as I know, no one has ever done the experiment of putting down recorders in multiple, distributed locations, evaluating them blind, and trying to correlate the number of EVPs found with violent death. That'd be an interesting experiment, but it would be tricky to do without confirmation bias.
I don't place much stock in EVPs, especially since the popular ways of gathering them seem optimized toward false positives. I did a small experiment of my own on them (which doesn't prove anything one way or the other), and wrote my experiences up here.