Some ghostly apparitions seem to have been accompanied by noise: footsteps, door-handle rattlings, raps. Such noises suggest some sort of impact on two different senses at once: that of sight and that of sound. They make little obvious sense: a weightless apparition should not make audible footsteps, and one that can go through a door would not have to rattle the handle. Poltergeists also produce raps. The whole social phenomenon of spiritualism developed from a rapping poltergeist in the household of Mr Fox in Rochester in the USA, in 1848.