What’s Really Going On: Infrasound
In the early 80s, a British researcher by the name of Vic Tandy, was working in his laboratory when he began to feel that something wasn’t quite right. He reported that he 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”. It was about then that he began to see a shadowy figure out of the corner of his eye, only to have it disappear when he tried to get a better look.
Then, one day, after a bracing fencing match, Tandy placed his sword in a vice in the lab for safekeeping and noticed that it was moving all on its own. Far from taking this as a sign that he was about to be run through by a ghost, Tandy immediately understood what had been going on.
The human ear can detect sounds within a range of 20 Hz to 20,000 Hz, and anything outside of that range is “silent” to humans. Anything with a frequency below 20 Hz is known as “infrasound” and, although they cannot be heard, their effects can still be felt.
The sound waves can agitate the stomach, creating a sensation similar to a release of adrenaline and a feeling of awe, panic or threat depending on the context. They can also vibrate the eyeballs, creating blurry images that aren’t there.
All sorts of natural and man-made objects can emit infrasound and, in the context of a creepy “haunted” environment, the effects can easily be interpreted as a ghoulish presence. Tandy soon discovered that a new fan had been installed in his lab that was emitting a sound at around 19 Hz. He turned the fan off and, voila, no more ghosties.