EVP is the acronym for Electronic Voice Phenomenon. An EVP is a disembodied voice that is recorded by an audio recording device such as a tape recorder, digital voice recorder or any audio recording device, including camcorders. Typically these voices are not discernable by the human ear and are only discovered upon playback of the recorded audio.

There are many theories concerning what these voices are and how they are picked up by recording devices. One thing is certain. They can be very compelling and nearly always excite the people who make the recordings. EVP's are not necessarily limited to voices. Other sounds, including animal and environmental sounds can be recorded as well.

The basic idea of an EVP relies on the theory that ghosts can manipulate energy. This energy manipulation is also associated with battery drains, a circumstance where fully charged batteries will be rapidly drained, theoretically by spirits draining the energy they need in order to manipulate the environment or manifest. If spirits use energy to manipulate the environment, they may also be able to manipulate electromagnetic waves. This manipulation of energy could account for the reasons that recording devices, both electronic (dvr) and magnetic (cassette tapes), can pick up these voices and the human ear (which functions on sound waves) cannot detect them.

Since recording devices work with either a powered microphone sending an electrical signal to a digital processor or an electrical signal to a magnetic recording medium, it makes sense that spirits could manipulate the signal to leave messages on the recorder, if you accept the theory of energy manipulation by spirits. Because the human ear detects vibrations of air molecules, you would not be able to pick up modulation of electrical signals, as is the primary theory of how EVP's are captured.

There are many types of EVP's which can be recorded so guidelines are needed. In order to provide a way to categorize EVP's, there is a generally accepted classification system consisting of three classes of EVP.
Class A
Class B
Class C
An EVP which is loud, clear, and is easily understood by most people. That means that most people hear the same thing without being told what the EVP is or what is being said.
An EVP which may be hard to hear without headphones and may sound like something different to different people. This is probably the most common type of EVP's.
An EVP that needs to be filtered and/or amplified in order to be heard and is generally hard to determine content. Often, some people will not even be able to hear a Class C EVP.

Using audio editing programs is the best way to isolate and filter the audio you have recorded. This can be quite tricky to do and requires either previous audio editing experience or a great deal of trial and error patience. Several tools are available for free but the best free program, in our opinion, is Audacity. It is fairly intuitive and offers a great selection of tools for editing audio. Probably the best program available is Adobe Audition. Audition was originally named Cool Edit Pro before Adobe bought it. Audition offers amazing control and editing capability but it comes at a hefty price. Audition has more bells and whistles than Audacity but there are really only a few that are needed for EVP work. Audacity has all of them. There is detailed information on using both of them in the Audio section of this site.

There are some very important things to remember when doing EVP sessions. An EVP session typically consists of recording while you ask questions. Sometimes it doesn't hurt to keep a recorder running even when you aren't asking questions but it is a matter of opinion. However you decide to conduct your EVP session, there are some key points to remember in order to keep any EVP's from being contaminated.

  1. Avoid holding the recorder in your hand. Try to use an external mic or lay the recorder on a stationary surface. The reason is that recording devices usually come equipped with a small condenser microphone. Condenser mics are very sensitive. If your thumb rubs across the body of the recorder, the mic will pick. Shifting your grip on the recorder will sound like a herd of bison running over your recorder.
  2. Movements can cause many false positives to show up on your recordings. Moving your arm wearing a long sleeve shirt can create sounds that can can be confused with 'yes' and 'no'. Moving your feet can sound like voices depending on what type of ground on which you're standing. Think of the sounds that your clothes make as you move and try to minimize them. The recorder will pick these up even if you aren't holding the recorder. If you become aware of clothing sounds during an EVP session, you might as well dismiss any whispered 'yes' or 'no' EVP's you think you've captured.
  3. Always speak in a normal voice when conducting EVP sessions, even when you are talking to your team mate. Whispers or speaking quietly can be muddled on the recording. For credibility purposes, it must be obvious when someone on your team is speaking.
  4. Vocally note any sounds you hear after they occur. It is important to make note in the recording when you hear camera shutter clicks, dogs barking, car or train noises, passing aircraft, or that censored word your team mate utters when he stumps his toe in the dark.
  5. Ensure that all possible man-made audio sources are turned off. Watch for radios, watch alarms, noisy neighbors, and especially members of your team who might be a little loud. Ideally, your team should be told you are conducting an EVP session and know to stay quiet. Try to minimize speaking to your team mate. EVP's can occur when your are speaking because the spirits aren't going to be polite and wait for you to finish talking about Monday's football game.