EVP,
For some information on how they do it (or think they do it), go to aaevp.com.
Macm is correct in that you can hear strong AM signals in wierd places. In my area, we have a clear channel AM radio station (700 WLWT), and I have heard it myself in bedsprings. I regularly hear it in my IR headphones when the base transmitter is off.
Anyway, EVP people think that they are hearing the voices of the dead in white noise.
The problem is that white noise (i.e. like the static you pick up on old AM or SW radios between stations) will also contain amplitude modulated signals and their harmonics on just about any tuner frequency. EVP is even worse than that. As I understand it, they
get a white noise source (a radio or TV tuned to static) and record it with a tape recorder or even a computer microphone and software. Oh yes, and while they have this setup running, they ask questions to which they expect answers (think of it as a talking electronic ouija board).
What they do next is mind-blowing. They play back the recording, listening for a response. if they dont get what they want, they play it fast, slow, backwards, isolate bands (with the software setup) until they hear something that sounds like an answer to their question.
Many will then clean it up and "enhance" the word or phrase, and then claim
They then go through the recording looking for the answers. And of course, they find them. There are many logical explanations for what they hear. It could be the local AM station, its harmonics, cross modulation (2 or more AM signals heard together) ,etc.
Randi has debunked these guys many times. The best way to debunk them is to let them record for at least 30 minutes. Every 30 minutes, any commercial radio station will give its station identification, which you will hear. If there is a strong AM or SW station in your area, simultaneously monitor it, time index it and the EVP recording, and you'll often find out the source of their ghostly message.
Many HAms also still use AM, and they are supposed to also give their call signals (though many dont).
Og course they will argue that they will put their white noise antenna in a shielded container, either ignorant of the fact that the tape recorder or computer circuitry itself will pick up strong AM signals and get them onto their recording medium.
But, I have argued this repeatedly with people who are convinced that they are the voices of the dead, and gotten nowhere with them. They are convinced, and like a hardcore religious belief, they wont accept any other explanation.
I have to remember that these are the same people who think Sylvia Brown is gifted, and are willing to pay her $650 per 1/2 hour to have her read them over the telephone.
But, as PT Barnum says, "there's a sucker born every minute". And I'm one of them. Instead of trying to debunk this stuff, and trying to tell people the truth, I should be out there holding EVP sessions and making $650/hour from them. Why do I bother trying to tell the truth when people would much rather believe a fantasy, and pay me for it too. Yes, it seems that I'm the idiot !
