"EVP" 

 Just Listen  

 Electronic voice phenomena (EVP) are electronically generated noises that resemble speech, but are not the result of intentional voice recordings or renderings.           

  Audio recorders have been taken on paranormal investigations and ghost hunts for years and have frequently recorded odd sounds. Most haunting involve some sort of unusual sounds, sometimes including whispering or voices.  These voices are usually  not heard at the time of the recording but only appear later during play back. It is, therefore, assumed by many people that the sounds must be paranormal in nature. Some people think that EVP voices are caused by 'spirits'. Some people believe that any sound or noise on caught their recorder is a spirit.  Since many people assume that 'spirits' are the same as ghosts (even though some investigations of a haunting generally fail to produce evidence supporting any such link), it probably explains why they seek EVP in haunted houses.  The seeking of EVP-type recordings on Paranormal investigations is different from traditional EVP research (also known as ITC or Instrumental Tran communication). ITC researchers generally maintain that the voices can be recorded anywhere at any time and use high levels of background noise(like the white noise of a radio not tuned in) so they generally will look for these evp anywhere at any time. Paranormal investigators, usually seek out evp when they are conducting some type of investigation for someone. They will usually find a quiet location during there investigation for recordings (though they may address questions out loud to any ghosts/spirit who might be present) to exclude the possibility of any natural voices. Even though these researchers and investigators conduct the evp sessions differently, they both are seeking the same thing.           

  When conducting an evp session I have to keep in mind that we are used to seeing and hearing at the same time, and when the lights go out during an investigation and we lose our sense of sight our sense of hearing gets increased. When our hearing gets increased, I think it becomes very easy to misinterpret noises and not realize their source. I think that if we are primed to hear something special, like a voice from a spirit, it is all too easy for the expectation to be fulfilled even when there are, in fact, natural causes (like another investigators voice) for it. I have to be aware of not only the other investigators but any natural noises and sounds that might be taking place. It is difficult for me to remember all the possible natural sources of sounds that where present during the investigation. One way that helps me with this problem is to prior to the start of the investigation is to conduct a quick run through of the place or area with a video camera and record any of the natural sounds. Some of these sounds would be like the air conditioner turning on and off, any leaking faucets or pipes. Having a video camera running during the investigation can also help with the location of a noise.

 Here is something else to consider during an evp session.

 I read this on the web and thought that it might be something worth sharing for you to think about. 

 Imagine you are at a noisy party with loud music and everyone talking. You're not paying any attention to the hubbub which is too difficult to listen to anyway. Then you hear your name mentioned. You look up and see it is someone you know on the far side of the room talking about you. The fact that you can suddenly hear your name among all the noise shows that hearing is something that happens not in your ear but in your brain. Your brain filtered out your name from the noise because it was relevant to you. This is the Cocktail Party Effect. It is significant here because people quickly get used to background sounds (even in noisy factories) so that they don't hear them any more - because the sound is not relevant.   

 The same can happen on paranormal investigations. Just because we don't remember hearing a weird sound during an investigation, we shouldn't be surprised that an audio recorder picked it up. A sound recorder is a neutral instrument that records everything within its capabilities without discrimination. It never gets used to background noises, like squeaky chairs and creaking floorboards. In addition, the recorder may actually be more sensitive to quiet sounds than the investigator. Many microphones are strongly directional so that they pick up sounds from one particular direction preferentially (more strongly than humans) while ignoring others. So a sound recorder may pick stuff we didn't hear and could also miss things we heard. In neither case does it mean the sound was necessarily paranormal, it is just that recorders work differently to human hearing.

 Another interesting point arises from the Cocktail Party Effect. Different people will get used to background noises at different rates. That means that some people may hear a sound whereas others don’t (because only some are already not hearing such noises)! Needless to say, if this happens many people will claim that the sound must be paranormal as only some people heard it. This sort of thing is frequently reported on investigations. I am not saying that these are the facts, I am just saying that this could be a possibility.

 Almost any simple noise, like white noise, can sound like speech if the person listening to it is in 'speech mode'. The more voice-like features in the noise (such as frequencies and rhythm), the more people will interpret it as words. Also, if the spectrum envelope of the sound (the overall frequency range) is restricted to that typical of a human voice, the illusion of speech is increased. Research has shown that people still understand speech even when it has been frequency shifted. Noise with these sort of characteristics is called 'formant noise' and it can sound like real speech. It can be good enough to trip the brain into 'speech mode'.

 So after all that do I think that EVP paranormal? 

 The existence of formant noise does not mean that EVP are paranormal. However, it does mean that precautions need to be observed when recording, processing and listening to EVP to avoid formant noise.

 For instance: Recording EVP

 •           use a good sound recorder in high quality mode - some EVP recordings have a restricted frequency range due to equipment limitations or using low quality or economy modes

 •           put the recorder down and don't touch it or anything in contact with it during recordings - to avoid accidental mechanical noises

 •           avoid file compressing sound files - compression and use of loss formats can alter noise 

 •           use two different model recorders together - to avoid internal noise or susceptibilities peculiar to a particular model of recorder Processing EVP 

•           don't edit or process EVP sound files - noise reduction software accentuates frequency peaks making apparent formants, if present, more prominent and reducing frequency range affects the spectrum envelope Listening to EVP 

 •           get a third party to judge recordings without telling them it contains apparent voices 

 •           play only 'answers' to judges from 'question and answer' sessions* to avoid suggestion effects   There are three classes of EVPs:

 Class A 

 Very clear Easy to understand

 Class B 

 Clear that the voice “doesn't belong” Less understandable than Class A but can be managed with amplification or editing software to clear off the background noise (NOTE: do NOT tamper with the voice and post that as evidence.  You can post the original recording and then post the “cleaned” recording listed with exactly what you did so someone else can replicate it) 

 Class C

 Potential voice Words undecipherable  

 I do believe that sometimes the spirits/ghost that we try to communicate with do so by our recorders. I believe that they have left use messages on them. Our jobs as paranormal investigators is to shift through the noises and sounds that we hear and record and find them. We should take an unbiased, logical, scientific, and professional approach when reviewing our audio data. While at the same time we attempt to discover the truth behind the event, in order to provide closure for all those affected; living or dead. ~Tracy