Ghosts

[Redbeard The Pink]

There's also some evidence to suggest that a great many ghost-related experiences are caused and/or enhanced by environmental factors that create some kind of low-frequency noise that can't quite be consciously noticed but is still unconsciously heard. Noises of that frequency are things we've actually evolved to be afraid of because the only natural phenomenon that make those noises are usually things that can kill us (earthquakes, big animals, stampedes, massive weather events, etc.).


When humans are exposed to sounds like these even in the absence of anything dangerous to make them, we tend to be set on edge and experience unexplained feelings of dread; some people even start to hear noises that aren't there and see things darting around the corners of their vision, following them, etc.


The first example of this I remember was from a story about an office building that was purported to be haunted in one section. When employees worked there, especially alone or at late hours, they would sometimes see and hear spooky things and have strange experiences. Investigation yielded that there was a malfunctioning fan in the ventilation system that was causing a bunch of the vents to thrum with a low-frequency sound. Once the fan was repaired, the experiences stopped and the office went back to normal.


Another example comes from research. Low-frequency sounds have been directed at unwitting crowds under various conditions, and crowds exposed to the sounds sometimes start getting agitated, even panicked. It's a weird phenomenon that warrants further study, but if there turns out to be anything to it then it could go a long way toward explaining certain paranormal phenomena.