I remember this article from when it came out; found it whilst looking for info on low frequency sound, it's very interesting, but was ignored by-and-large by the spook community as it's less rimantic than dead grandpa's.
http://users.iafrica.com/s/sa/salbu/apollo/HumA.html
Monday 29 June 1998
Science finds reasons for ghostly'hauntings'
ULTRA-LOW SOUND WAVES BLAMED FOR VISIONS, FEELINGS OF TERROR
Robert Matthews
The Sunday Telegraph LONDON -- Ghosts may have a scientific explanation after all.
New research into a real-life "haunting" has revealed that all the classic signs of ghosts can be explained as the result of very low-frequency sound waves trapped inside buildings. The sound waves -- capable of being triggered by nothing more than the wind passing over walls -- cannot be heard by human ears. But scientific tests have revealed that they have effects on the human body that can account for visions of wraith-like appearances, and even the feelings of cold and terror that accompany them.
The explanation emerged after a chance discovery by a university academic who found himself involved in a haunting late one night in the laboratory of a medical manufacturing firm in England. Vic Tandy, an expert in computer-assisted learning at Coventry University, had been told that the building was haunted, but dismissed it as a joke.
He changed his mind after the events that unfolded one night as he worked alone in the office. "I began to feel increasingly uncomfortable, " he recalls. "I was sweating but cold, and the feeling of depression was noticeable -- but there was also something else. It was as though something was in the room with me. " "Then I became aware that I was being watched, and a figure slowly emerged to my left. It was indistinct and on the periphery of my vision, but it moved just as I would expect a person to. It was grey, and made no sound. The hair was standing up on the back of my neck -- I was terrified. " Mr. Tandy plucked up courage to look at the apparition face-on -- only to see it fade and then vanish. "I decided I must be cracking up, and went home. "
The explanation emerged the following morning. Mr. Tandy, a fencing enthusiast, was modifying one of his swords and had left the blade clamped in a vice while he went in search of oil. "When I returned, I noticed that the free end of the blade was frantically vibrating up and down, " he said. Mr. Tandy, a trained engineer, realized the blade might be receiving energy from very low-frequency sound waves filling the laboratory -- so low that they could not be heard.
Tests duly revealed the existence of a "standing wave" trapped in the lab which reached a peak in intensity next to Mr Tandy's desk, where he had been working when he saw the "ghost. " "It turned out to be caused by a new extraction fan which was making the air vibrate at about 19 cycles per second. When the fan's mounting was altered, the ghost left with the standing wave. "
Working with Dr. Tony Lawrence of the university's school of health, Mr. Tandy has now discovered the significance of this rate of vibration. In research published in the latest issue of the Journal of the Society for Psychical Research, they reveal that "infra-sound" around this frequency has been linked to a whole host of physiological effects --including breathlessness, shivering and feelings of fear.
Most significantly, research by NASA, the U. S. space agency, has shown that the human eyeball has a resonant frequency of 18 cycles a second, at which it starts to vibrate in sympathy to infra-sound. "This would cause a serious smearing of vision, " says Dr. Lawrence.
While acoustic experts have known about the health effects of infra-sound for many years, before now no one had made the link to ghost sightings. Mr. Tandy said he has since come across two more "hauntings" where low-frequency sound may be to blame. "One occurred in a corridor of a building that had a wind-tunnel in the basement, and it was operating at the time of the sighting, " he said. He added, however, that the wind blowing over a window in a side wall of a long corridor might be enough to create a standing wave, similar to that formed by a person blowing over the neck of a bottle. "It would be interesting to look at reports of haunted houses, to see if the "ghosts" tend to appear in long, windy corridors. "
The discovery of the infra-sound effect is already creating a stir among experts in paranormal phenomena. "It is very interesting, as it gives us another scientific variable we can fit into the picture, " said Professor David Fontana of the University of Cardiff, a former president of the Society of Psychical Research. But Mr. Fontana insisted that infra-sound was unlikely to be the final answer. "It cannot explain those cases where there is some interaction between the person and the apparition -- as there is with poltergeists, for example. The problem is that whenever you get a potential explanation like this, you find that there are a whole lot of things it cannot account for. "
Keep on rocking in the free world...