Also known as Raudive voices, the phenomenon of mysterious voices, apparently from dead individuals, impressed on tape recordings made on unmodified standard recording apparatus. The phenomenon was discovered by Friedrich Jurgenson in 1959 but was extensively pursued and popularized by Konstantine Raudive, a Latvian psychologist and parapsychologist. Jiirgenson, a painter and film producer, discovered the phenomenon one day after recording the song of a bird on his recorder. Playing it back, he heard a human voice. He repeated the process, after initially concluding that the voice was due to a fault in his recorder. However, when the phenomenon reappeared, and he listened to what was being said, he concluded that he had received a message from his deceased mother.
After having learned of Jurgenson’s experience, Rau- dive contacted him and convinced him to cooperate in five years of further research in attempts to receive para¬ normal voices on tape. The two men disagreed and separated in 1969. Raudive published the results of their research, which became widely known, after the appearance of an English edition, as Breakthrough: An Amazing Experiment in Electronic Communication with the Dead (1971). The phenomenon was of some interest to parapsychologists, who saw the possibility of conducting survival research without the need of a medium.