Senses used by mental mediums are sometimes defined differently from in other paranormal fields. A medium is said to have psychic abilities but not all psychics function as mediums. The term clairvoyance, for instance, may include seeing spirit and visions instilled by the spirit world. The Parapsychological Association defines "clairvoyance" as information derived directly from an external physical source.[37]
In 1925, Samuel Soal claimed to have taken part in a series of séances with the medium Blanche Cooper who contacted the spirit of a soldier Gordon Davis and revealed the house that he had lived in. Researchers later discovered fraud as the séances had taken place in 1922, not 1925. The magician and paranormal investigator Bob Couttie revealed that Davis was alive, Soal lived close to him and had altered the records of the sittings after checking out the house. Soal's co-workers knew that he had fiddled the results but were kept quiet with threats of libel suits.[145]
In the later half of the 20th century, Western mediumship developed in two different ways. One type involved clairaudience or sensitives who hear spirit, and then relay what they hear to their clients.[29] The other incarnation of non-physical mediumship is a form of channeling in which the channeler goes into a trance, or "leaves their body", allowing a spirit entity to borrow their body, who then speaks through them.[30] When in a trance the medium appears to come under the control of the spirit of a departed soul, sometimes entering into a cataleptic state,[31] although modern channelers may not.[citation needed] Some channelers open the eyes when channeling, and remain able to walk and behave normally. The rhythm and the intonation of the voice may also change completely.
Colin Fry was exposed in 1992 when during a séance the lights were unexpectedly turned on and he was seen holding a spirit trumpet in the air, which the audience had been led to believe was being levitated by spiritual energy.[186] In 1997, Massimo Polidoro and Luigi Garlaschelli produced wax-moulds directly from one's hand which were exactly the same copies as Gustav Geley obtained from Franek Kluski, which are kept at the Institute Metapsychique International.[187]
The Polish medium Stanisława Tomczyk's levitation of a glass beaker was exposed and replicated in 1910 by the magician William S. Marriott by means of a hidden thread.[117] The Italian medium Lucia Sordi was exposed in 1911, she was bound to a chair by psychical researchers but would free herself during her séances. The tricks of another Italian medium Linda Gazzera were revealed in the same year, she would release her hands and feet from control in her séances and use them. Gazzera would not permit anyone to search her before a séance sitting, as she concealed muslin and other objects in her hair.[118]
^ "Glossary of Key Words Frequently Used in Parapsychology" Archived 2010-12-24 at the Wayback Machine, Parapsychological Association website. "Materialization: A phenomenon of physical mediumship in which living entities or inanimate objects are caused to take form, sometimes from ectoplasm." Retrieved January 24, 2006 "Medium – Definition". Retrieved 23 March 2007.