Investigation of EVP is the subject of hundreds of regional and national groups and Internet message boards. EVP is the recording of otherworldly voices onto tapes, reel-to-reels and other types of recording equipment.
Voices are rarely heard during recording -- only during playback. They may be so soft that they can barely be heard or so distorted that they must be listened to over and over again to determine their meaning. Regardless of how clear the recording is, the voices rarely speak for more than a few seconds at a time. Researchers spend hours listening again and again to decipher the meaning behind just a few seconds of sound.