 When professional ventriloquist Ray Alan visited the house and concluded that the girls were faking an allegedly "demonic" voice because they "obviously loved all the attention they got", Grosse was so convinced it was of supernatural origin that he offered £1,000 to anyone who could duplicate the voice by ventriloquism or any other form of trickery.The parapsychologist David Fontana proposed that poltergeists could haunt tape recorders and speculated that a peculiar threading jam experienced by Grosse while playing tape recordings made at the home was due to supernatural forces.However, Tom Flynn, a media expert for the Committee for Skeptical Inquiry examined Fontana's claims and suggested an entirely naturalistic explanation.