Electronic Voice Phenomena (EVP) is the appearance of sounds and possibly intelligible voices on recording media that have no known physical explanation. Such voices are generally thought to originate from deceased persons. This is the primary reason that people first began experimenting with EVP. Others study EVP to better understand how and why it works, and to improve EVP experimental techniques.

The recording equipment need not be expensive or elaborate to work with EVP. As in any field of interest, some people are better at recording EVP than others. With patience, perseverance, and good listening techniques, you should be able to record and hear EVP messages.

The recorded voices may be very quiet and are often difficult to hear and understand at first. Most EVP experimenters say that they have developed an “ear” for the sounds, after learning to distinguish them from background noise. The voices can often be recognized as male or female, young or old. Messages usually last two seconds or less and are most often two to four words. The words may be spoken very quickly, and there is often a distinctive cadence to EVP voices.

The idea behind recording an EVP is to attempt have a conversation with the ghosts. Ask them a question, wait a few seconds, then ask another question. It's not important to actually hear the ghost's response to the questions.   Listen carefully from the beginning to the end for anything out of the ordinary. It has been reported in some haunting cases that the ghosts at the site have answered the ghost hunter's questions. You have to listen closely, the answers are not always clear, and may even be in a different language.

Unlike the the movie "White Noise" with Michael Keaton and the statement that a major percentage of EVPs were threatening in nature, most EVPs are a few simple words.  Most EVPs are rapid, faint, and often spoken in grammatically unusual and simplified language—or even multiple languages during the same sentence. The interpretation of such recordings is often highly subjective, and may differ from listener to listener; some listeners may hear nothing at all, while others report hearing specific phrases or sentences.

• Audio Recorder: EVP has been recorded on all types of equipment. The built-in microphone on a portable tape recorder tends to pick up motor noise. Therefore, it is best to use an external microphone. It is also best to use a cassette tape deck with mechanical controls that allow easy, repeated review of the voices. Be sure the recorder has a counter. People report recording EVP on telephone answer machines and many other devices that do not have external microphones. IC recorders (digital note takers) are fast becoming the recorder of choice, but they are best used with a computer to analyze and store the recordings.
  
  
• Microphone: A microphone will help you make a record of your comments during the recording session, and introduce external sound sources. EVP messages will be easier to review if documentation/notes of the questions asked and the recording circumstances.
  
  
• Headphones: Since the EVP voices frequently are not loud, many voices will be missed unless headphones are used. 
  
  
• Tape: Any low noise, high sensitivity tape may be used. 60-minute tape (30 minutes each side) is recommended. Each session requires a new, unused tape.  Previous recordings may bleed through causing distortion or false positives.
  
  
• Speaker: A separate speaker is not necessary but with the speaker, those participating in the review will be able hear.