EVP: Electronic voice phenomena; ghostly voices recorded on audio or video tape; voices recorded on audio media that are only detected during playback.
There are three classes of EVP, as described by scientist Konstantin Raudive:
Class A: Voices can be heard and identified by anyone with normal hearing and knowledge of the language spoken; no special training of the ear is needed to detect them.
Class B: Voices speak more rapidly and more softly, but are still quite plainly audible to a trained and attentive ear. The ability to differentiate increased with practice. but this is a slow and wearysome process. For this reason it is difficult to use non-regular participants for experimental purposes with class B voices.
Class C: Consists of the most interesting voices; voices that give us a great deal of information and much paranormal data. Unfortunately, these can be heard only in fragments, even by a trained ear, but with improved technical aids, it may eventually become possible to hear and demonstrate these voices, which lie beyond our range of hearing, without trouble.
There was an EVP voice which seemed to come from an unknown source. The EVP was examined at PAS Headquarters, then sent to Steve for further analysis.
Steve's Scientific Conclusion:
The sound appears to be something banging somewhere else. It is very low and so might appear as anything. Here is a greatly amplified version showing the wave and spectrum.
"I did a time stretch on the evp and have included it for your listening pleasure. It is really weird. It sounds like cool-like-cool, and is completely imbedded in noise. I can't seem to filter out the noise and separate the noise from the voice. The ringing sound is an artifact from the extreme time stretch and not part of the original evp. The initial knock is actually composed of 4 distinct knock waveforms in succession. Each knock waveform decays and repeats itself. I have included a picture of that in the file knock.jpg. Because the waveform is completely imbedded in noise, you can't get a clear spectrogram. However, the knock has a really strange spectrum, and is not like an ordinary knock."