Infrasound and the Paranormal

There may be an explanation for many paranormal events from Cryptozoological sightings to ghosts.

That explanation is what scientists call Infrasound

This is sound that is below the normal threshold of human hearing, usually in the 16 or 17 hertz range.

I initially got clued into it reading about how tigers can emit low frequency sounds causing various effects in their prey. Now they don't apparently use it purposely (like killer whales do sonar), preferring to escape the majority of the time, but it's been reported and studied.

One account is that the person finds themselves rooted to the spot. Other creatures that can emit them (as per the Wiki page) are Rhinos, Okapis, Giraffes, Hippos, and Lions. Of course we know that Cetaceans can also generate them and those long wave subsonics are how Blue whales communicate over long distances.

In the case of some ghost sightings, it may be possible for structures in old building and on board ships to rub together to create a type of infrasound. Certain people may be more or less sensitive to these effects, and they could possibly explain those 'out of the corner of the eye' type phenomenon. If the infrasound causes the human eye to vibrate, it could cause temporary hallucinations.

Now, this is not a new theory. It's been around since at least 2003 when British researchers looked into it at the National Physical Laboratory in England.

CNN

Feel a ghost? Perhaps it's infrasound

MANCHESTER, England (Reuters) -- Mysteriously snuffed out candles, weird sensations and shivers down the spine may not be due to the presence of ghosts in haunted houses but to very low frequency sound that is inaudible to humans.

British scientists have shown in a controlled experiment that the extreme bass sound known as infrasound produces a range of bizarre effects in people including anxiety, extreme sorrow and chills -- supporting popular suggestions of a link between infrasound and strange sensations.

"Normally you can't hear it," Dr Richard Lord, an acoustic scientist at the National Physical Laboratory in England who worked on the project, said on Monday.

Lord and his colleagues, who produced infrasound with a seven meter (yard) pipe and tested its impact on 750 people at a concert, said infrasound is also generated by natural phenomena

"Some scientists have suggested that this level of sound may be present at some allegedly haunted sites and so cause people to have odd sensations that they attribute to a ghost -- our findings support these ideas," said Professor Richard Wiseman, a psychologist at the University of Hertfordshire in southern England.

In the first controlled experiment of infrasound, Lord and Wiseman played four contemporary pieces of live music, including some laced with infrasound, at a London concert hall and asked the audience to describe their reactions to the music.

The audience did not know which pieces included infrasound but 22 percent reported more unusual experiences when it was present in the music.

It might not be a bad idea for 'ghosthunters' to ditch their EVP recordings and invest in an infrasound detector.