Personally, I'm inclined to chalk EVP up to "All in your head", and for good reason. I'll explain.
Look at something. Let's say, for the sake of arguement, a field with a forest behind it. You see trees and leaves and grass. Or do you? In fact, you actually *see* very little of that, and your brain simply "fills in" the rest, painting the picture in completeness from incomplete and momentary sensory information. That's why camoflage works: because you don't pick out the outline (there are entire sections of the occipital dedicated to just that), your brain "paints over" whatever it was, and it is, in effect, invisble. However, when the camoflaged animal moves, your brain focuses on the movement and, by focusing, becomes able to detect the formerly 'invisble' animal.
See, our brain isn't just like a computer. It doesn't recieve from every pixel, and store perferct images, unless it's focused. Our brains are pretty much just pattern-recognition machines. And that's where EVP comes from; pattern-recognition, even when there's nothing there. It's homologous to when you hear someone say your name in a talkative crowd; nobody did, but all of their voices combined happened to randomly produce a sequence on phonemes which your brain interpreted as your name, thus you 'heard' it.
Same thing with EVP. The static will randomly fluctuate in pitch, and if these random fluctuations happen to be close enough to the pitch fluctuations that we perceive as words, we 'hear' a 'voice'. It's nothing but misplaced pattern recognition trying to make sense of random noise.
At least, that's my opinion on the subject. But I'm something of a skeptical spoilsport in these matters.
Henry Astley
