Patrick, how do you insure your evidence, such as EVP, is not contaminated by ambient noise? Especially recording it live outside on the street?
That’s an excellent question. Quite simply – you can’t.
However, you can’t prevent contamination indoors either.
Some might think that by recording EVP indoors, it will insure that the problems of street level, outdoor contamination will be eliminated. It’s a nice thought in theory, but it doesn’t work out that way in practice.
Why not? Because the microphone and your recording device do not always hear sound the way your ear hears it. Audio recording equipment can amplify faint sounds. Sounds that are sometimes too faint for us to immediately recognize. I can’t tell you how many recordings I’ve conducted indoors, only to hear a distant car, or dog barking, or plane passing overhead that we didn’t note at the time we conducted the recording.
Then there is the whole argument about what EVP actually IS – are they inaudible sounds in frequency ranges that our ears can’t natively detect? Or is EVP an electromagnetic component that occurs in the RF radio spectrum? Are they both? We don’t know for sure. Unless you’re conducting your EVP in a sound proof booth placed in a Faraday cage (a structure that shields electronics from RF interference) it is going to be prone to contamination. Period.
So how might someone know if that voice that showed up on the recorder is a possible spectral voice, or contamination from ambient noise? One popular method is to “tag” ambient sounds as you hear them during a recording “NOTE – someone in the group coughed… NOTE – car passing outside…”
However even this method is not foolproof, as we have already discussed how ambient noise might be too low in fidelity to be detected by our ears. Live monitoring of a recording session over headphones can help, but we have instances where the EVP is only audible after the recording session is over on playback.
By definition, all EVP recordings – regardless of the great lengths a researcher might go to prevent contamination – are going to be suspect under the scrutiny of scientific peer review. Electronic Voice Phenomena is just that – a phenomena – a fact or situation that is observed to exist or happen, especially one whose cause or explanation is in question. One that is little understood, even after over half a century of documented cases.
Like all paranormal phenomena, EVP is largely a matter of personal belief and opinion. Until the paranormal can be conclusively proven scientifically (which it may well never be) it is a curious conjecture.