The historical development of ITC has been treated extensively in the literature. Beginning with the 20ies in our century several mediums predicted technical contacts explaining that entities in the beyond were working for it. Early experiments – partially successful – remained unnoticed (see f.i. Weinberger). The first to go public were the pioneers Juergenson, Raudive and others since about 1960 presenting apparently paranormal voices on magnetic tapes. Around the 80ies several experimenters observed stronger effects: the already mentioned direct electroacoustic voices with high volume and good understandability, single images on video-tapes, short sequences of images on TV-screens, and finally page-long texts in computers.
Compared with the many thousand people trying to find voices on their tapes, the number of “higher developed” experimenters/operators – known to the author – remained rather small so that an overview is possible. Most of the phenomena treated in the following paragraphs developed through many months of extensive patient experimentation. The involvement of personal psychic components or faculties is clearly to be recognized.