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I only recently got wind of this. I heard some little blurb about Paranormal Activity using this—infrasound.

Hmmmm. Oh reallyyy?

On the one hand, I felt violated.

I am an unbeliever. I am not superstitious. I don't believe in demons or ghosts or whatever. And yet, this film had me on edge long after seeing it. I also know that my movie pal of the time, my dad, was also on edge after seeing it, though he was not an atheist like me. I saw the film's flaws, its hokey acting at times etc. I feel it did not "earn" such an effect on me.

And yet it did have.

On the other hand, perhaps this new information helps to explain its power over me and my dad, which in its way is comforting.

And Irreversible

That film would probably be unsettling regardless. But, what influence did use of infrasound have on its viewers?

What other films have or will make use of this trick?

So, I think it begs the question: is it ethical?

Is it just like any other trick, any other manipulation that filmmakers or other showmen use? Or is it different, since it's under the radar, not readily apparent, and I bet, not commonly known of, unlike audible sounds, or other musical or visual elements etc?

This is something, I bet, most people are unaware of, something that triggers our monkey or lizard brains in a negative way, or with a negative result. Is it an ethical concern, or none such?

Full disclaimer: my concern would not necessarily keep me from using it as a tool! xD I am not sure. I am asking for thoughts. I kind of feel like films using this tactic should disclose the fact…perhaps at least until it becomes common knowledge we are being manipulated in this new way. LOL.

How the Hidden Sounds of Horror Movie Soundtracks Freak You Out

The Science of Silence: Disquieting Uses of Infrasound in Movies
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I was totally unawares!
The very origins of the moving image was based on (cheap) spectacle. Was it not 'manipulation' when it was discovered that the eye could be tricked at an optimal 24/25 FPS?
I am very interested, and when I begin my next production, I will research further.
Thank you for the links.
I would say it's absolutely ethical, in exactly the same way its ethical to stab a cabbage for the sound effect it produces, or use makeup and prosthetics to fake a wound.

On a side note: I know a friend of mine years ago was a PhD student at the Institute for Sound and Vibration Research. He told me of a study where they made a mockup of a helicopter interior and played sounds with speakers in different positions to make people believe they were really in a flying aircraft. One thing they found was that people were much more likely to believe the mockup if there was a 0.5 Hz thump playing (lowest textbook audible frequency is 20 Hz).


IndieTalk's Resident Guru
How about this disclaimer in front of all films:

What you are about to see is designed to manipulate your
senses and feelings. We use audio and visual tricks and editing.
You use every tool available. There are all kinds of sounds that raise our vestigial hackles (predators) and "conditioned" sounds like emergency vehicles and alarms. In Hitchcocks "Strangers On A Train" a feline roar (tiger, I believe) was used when the train went into a tunnel. My only personal "issue" with infrasonic sound is that it doesn't translate across most audio playback systems; not many speakers can handle sub-80hZ frequencies. So I will use every other trick I can think of before infrasonics so my sound design will translate across platforms that cannot reproduce very low frequencies.