Shhh you hear that? Yeah I don’t either…
but it’s making me feel creeped out. Hey guys julia here for DNews The world is loud and noisy. And it seems
to be only getting noisier. Obviously exposure to loud noises can cause hearing damaging.
But some studies like one published in the British Medical Bulletin, show that it cause
a range of ill health effects, like anxiety and stress, and another study showed it may
even raise blood pressure . And that’s just the sounds you can hear. There’s a whole
world of sound that’s below our range of hearing that can also be damaging. Infrasound typically describes sound below
20 hertz. Usually, it’s too low for humans to pick up, yet some animals communicate in
this range. Like elephants vocalize in a low rumble that we can’t hear. But infrasound
can be artificial too: loudspeakers and public address systems, industrial machinery, that
kind of thing, can kick out sounds that are too low in frequency for humans to hear, but
can make us sick. A study published in the journal indoor and
built environment found that infrasound could be contributing to a condition called “sick-building
syndrome”. A condition where office workers complain of nausea, dizziness, migraine, fatigue
and tinnitus with no attributable cause. Yet this study suggests that infrasound, typically
of about 7hz, might be responsible. Unfortunately, infrasound isn’t regulated
all that well. A recent report in the Proceedings of the Royal Society A questions the idea
of what makes up “safe” sound levels in a working environment. The report suggests
that workplace exposure to both infrasound and ultrasound often exceeds current guidelines.
There’s concern too that the guidelines are too low, and outdated: coming from research
that’s 40 years old. And even then the evidence for the guidelines isn’t strong enough,
they are based on the average response of small group, often of adult males. The researchers
back then didn’t didn’t reach any strong conclusions, just preliminary guidelines,
believing that more research would be done. But in the ensuing decades, not much has changed.
So basically the lead author is saying… “more research is needed”. But there is evidence that infrasounds cause
more than just headaches. Some researchers think it might be responsible for that creepy
“haunted house feeling”. One paper published in the journal of the Society for Psychical
Research suggests that a standing sound wave of specifically 18.9 hertz is responsible
for some of the spooky happenings in their lab. Researchers at Coventry University kept
seeing moving things out of the corners of their eyes, their hair kept standing on end,
they felt simply dreadful anytime they were in the lab. But one day they noticed a piece of equipment
was vibrating without an apparent cause, and discovered that an extractor fan was creating
a standing wave at, you guess it, 18.9 hertz. When they turned off the fan, one of the authors
described the feeling as “if a huge weight was lifted”. And researchers have tested this on a larger
audience. Literally. British scientists played music to a large auditorium filled with people…and
slipped infrasound into some of the songs. Some people in the audience said they felt
“uneasy or sorrowful, getting chills down the spine or nervous feelings of revulsion
or fear” when the songs contained infrasound. Spooky right? No, it’s science. But don’t be so put off by soundwaves yet.
Not all of them are creepy! in fact soundwaves can do some pretty cool stuff! To learn more
about how scientists are harnessing the power of sound, check out this episode right here. TestTube now has a newsletter! Get a weekly
round-up of our most popular videos across all our shows at TestTube.com/fwd So have you ever gotten that creepy feeling?
Or felt sick in your office or school for no reason? Do you think it was infrasound?
tell me your stories down below