Creating Electronic Voice Phenomena (EVP) through Ultrasound

Hi there,

I just made a video on how one can fake Electronic Voice Phenomena (EVP) without manipulating the recorder or the recorded files. It shows how to create an ultrasound sample that is inaudible but can become audible when recorded by a digital recorder or tape recorder.
This is not meant as a claim that all EVP would be faked, it rather points out how frauds could create EVP.
Check the clip for a full explanation and demonstration:

www.youtube.com...

Cheers,
Burkhard

PS: Sorry, I could not get the Youtube-Video embedding running.

[edit on 28-12-2009 by Verklagekasper]

Great stuff! very interesting

I've heard some great evp's and this is an interesting look at how it can be faked, the best one's are where random question's are asked and their's a response, obviously this could be faked aswell but the timing of the responses could be taken into account here, would be maybe more noticable.

Hi great video.

Got some questions for you. Bare in mind i have no experience in this field lol.

1. If you had an E.V.P that you suspected was fake. Would you be able to reverse engineer it to end up with the original voice recording?

2. I know you layed out what equipment you would need, but im unsure as to what regular recorders could pick up. So would this work on a regular shop bought recorders?

3. Are there any external proceses that may do something similar that people could confuse as E.V.P ei. T.V or Radio work for example?

All very interesting, ive always suspected that E.V.P could be faked and you've just proved it for me. Your video is now in my Evidence collection.

Fantastic Stuff.

Originally posted by Algebra
1. If you had an E.V.P that you suspected was fake. Would you be able to reverse engineer it to end up with the original voice recording?

Generally, no. Well, except maybe for an aliasing signal that aliases to the "wrong" frequency range, hence sounding all distorted. You could shift that by amplitude modulation, making it understandable again. But otherwise, you cannot improve what you get. Just as you cannot get the original HIFI sound out of a poor AM radio signal.
For that matter, noise removal filters which are often used to "clean up" EVPs do not restore the original signal. They just make an educated guess which parts of the signal to tone down and which to enhance. If you had a sample that sounds a little bit like a voice, the noise removal filter may make it sound a bit more like a voice. It hasn't become closer to the "original" sample, though. The noise removal filter only creates its own interpretation. For that reason, the more serious EVP researchers refuse to "improve" or otherwise tamper with the recorded sound.

2. I know you layed out what equipment you would need, but im unsure as to what regular recorders could pick up. So would this work on a regular shop bought recorders?

I guess with a tweeter box that can play frequencies up to 50kHz, you should be able to produce EVPs on mid-end recorders sampling at 22kHz or 11kHz pretty well. If you don't only have such a tweeter box but also an external microphone that can catch frequencies up to 50kHz, I'm pretty sure you can create an EVP on any recorder.

3. Are there any external proceses that may do something similar that people could confuse as E.V.P ei. T.V or Radio work for example?

Yes, you can receive signals from radio transmitters or walkie talkies:
www.physicsforums.com...

However, modern functional audio gear shouldn't be prone to this.

All very interesting, ive always suspected that E.V.P could be faked and you've just proved it for me. Your video is now in my Evidence collection.

Fantastic Stuff.

Thanks!

S&F

That video is excellent, thanks you for taking the time to do it.

One question I was unclear on (sorry if it was answered in the video) would there be any way that one could analyse an EVP and prove it was in fact an ultrasound - such as any recognizable distortions coming from the process of producing an ultrasound as yours? Some sounds analysis that could be used to prove or disprove the legitimacy of an EVP?

Originally posted by InTrueFiction
That video is excellent, thanks you for taking the time to do it.

Thank you!

One question I was unclear on (sorry if it was answered in the video) would there be any way that one could analyse an EVP and prove it was in fact an ultrasound - such as any recognizable distortions coming from the process of producing an ultrasound as yours?

No, this is not possible. There is no special quality to aliasing or distortion artifacts that would make them identifiable as such.