# Does 18hz audio ("infrasound") make people see ghosts?

**URL:** <https://boards.straightdope.com/t/does-18hz-audio-infrasound-make-people-see-ghosts/557518>\
**Category:** Factual Questions\
**Created:** [October 18, 2010, 2:57am UTC](https://boards.straightdope.com/t/does-18hz-audio-infrasound-make-people-see-ghosts/557518 "2010-10-18T02:57:04Z")\
**Posts on this page:** 2\
**Page:** 2

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**Author:** ![jackdavinci](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackdavinci/32/3259_2.png) [@jackdavinci](https://boards.straightdope.com/u/jackdavinci)\
**Post date:** [October 19, 2010, 7:21am UTC](https://boards.straightdope.com/t/does-18hz-audio-infrasound-make-people-see-ghosts/557518/21 "2010-10-19T07:21:32Z")

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> [@Fridgemagnet](#):
>
> Similar effects were investigated in the Haunt Project, an attempt to induce supernatural sightings by means of infrasound and electromagnetic fields

I hadn’t heard of the infrasound effect, but I have heard of the electromagnetic field effect.

Seems silly to use computer for their AWESOME POWER TO DETECT 18 Hz IN YOUR ENVIRONMENT, when you could just use it’s awesome power to… GENERATE an 18 Hz and find out for yourself. Assuming computer speakers have that range.

In other news, a simple google search claims that 18 Hz is ALSO the legendary “only teens can hear it” tone. Coincidence?

OK I tried generating an 18Hz tone with Audacity. I probably could have tried a slight range rather than only 18Hz and whatever other conditions to make it scientific, but I just held the speaker in front of my eye at various distances until I felt something. While I did feel like there was a slight pressure on my eye, my vision did not change at all. I invite others to do a more rigorous testing. But in principle, I would think that at best, stimulus of the eye would only activate phosphenes, which while they make pretty geometric patterns, they generally don’t look anthropomorphic.

Seriously, I invite others to experiment on themselves.

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**Author:** ![bluezooky](https://avatars.discourse-cdn.com/v4/letter/b/e8c25b/32.png) [@bluezooky](https://boards.straightdope.com/u/bluezooky)\
**Post date:** [October 19, 2010, 7:48am UTC](https://boards.straightdope.com/t/does-18hz-audio-infrasound-make-people-see-ghosts/557518/22 "2010-10-19T07:48:05Z")

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> [@Simplicio](#):
>
> What **BigT** said. The point is that the wikipedia article isn’t just throwing around scientific terms at random like Deepak Chapra randomly inserts “quantum” into sentences to add the veneer of science, as you suggest. The resonant frequency of the eye is a real thing and it has a measurable physiological effect thats at least conceivably related to the phenomena being discussed.
> 
> As to the larger theory that 18Hz noise cases haunted houses, I don’t think thats woo either. It might not br true, but its supported by at least some empirical evidence (the skepic’s dictionary mentions at least one published study, wikipedia a second).
> 
> Indeed, its sort of the opposite of woo, in that its seeking a naturalistic explanation for supposed supernatural phenomena and then using experiments to back up the explanation.

There supposedly some sacred sites such as caves or ungroundrooms in UK dating back to the Stonehenge era that have this infasound effect. Human senses are a funny thing, as senstive as they are inaccurate.

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