Electronic Voice Phenomena (EVP) : When voices and noises are recorded on audio equipment, but are usually not audible to the human ear at the time of recording. They are typically graded via an A, B, C rating system, with A being the clearest and most likely of being paranormal. At times, a disembodied voice may be physically heard and also picked up by the recording device. These, along with other unexplained sounds, we refer to as audio anomalies.
Thomas A. Edison pioneered the idea of recording spirit voices in the 1920's. His mother who was very ill at the time was soon to die and Edison wanted to find a way to communicate with her after she had passed. Along with his assistant Dr. Miller Hutchinson they worked on a device called the Thomas Edison Communicator. The design was a large microphone that was to pick voices out of the air. Unfortunately Edison passed away before the device could be completed.
American photographer Attila von Szalay was among the first to successfully record voices of the dead as a way to augment his investigations in photographing ghosts. He began his attempts in 1941 using a 78 rpm record, but it wasn't until 1956, after switching to a reel-to-reel tape recorder, that he believed he was successful.
Working with Raymond Bayless, von Szalay conducted a number of recording sessions with a custom-made apparatus, consisting of a microphone in an insulated cabinet connected to an external recording device and speaker. Szalay reported finding many sounds on the tape that could not be heard on the speaker at the time of recording, some of which were recorded when there was no one in the cabinet. He believed these sounds to be the voices of discarnate spirits.
Among the first recordings believed to be spirit voices were such messages as "This is G!", "Hot dog, Art!", and "Merry Christmas and Happy New Year to you all". Von Szalay and Raymond Bayless' work was published by the Journal of the American Society for Psychical Research in 1959.Bayless later went on to co-author the 1979 book, Phone Calls From the Dead.
In 1959, Swedish painter and film producer Friedrich Jürgenson was recording bird songs. Upon playing the tape later, he heard what he interpreted to be his dead father's voice and then the spirit of his deceased wife calling his name. He went on to make several more recordings, including one that he said contained a message from his late mother