Brown Noise

[Myrol]

Hello! Well, a month or so ago whilst watching "Brainiac" I've seen a funny but very embarrasing thing wich is quite confusing for me!

22725Hertz and MINUS 30Decibel are called as the "Brown Noise", I was a little unsure where to post it because you can use it as a WEAPON.

All People within 1m radius of the speaker get immediately diarrohea and WILL poo their pants if the Brown Noise is active. Wilson Harber (I think) was the "inventor" of this sound and because I had seen how a victim suffered under this sound I can promise IT WORKS!

They said, it brings your bowel (intestines) to a fatal vibration wich results in sudden rush of crap, even if you squeeze your bunghole like hell :p

Imagine: An important leader from a company makes a presentation and a bored collegue activates a nearby speaker with brown Noise to stop the presentation IMMEDIATELY :D

[Cyclonite]

So that really works? I saw it in southpark once. Funny stuff

[xyz]

There was a thread or two a while ago about using infrasound, a search should find them.

[kingspaz]

I've just tried this now. I used a tone generator program generating a sine waveform. The frequency was plugged in and the volume of the speakers taken from 0-highest (the assumption -30DB is between 0 and highest was taken). The noise is not very pleasant but I didn't shit myself!

edit: I do feel like I need a shit now, although thats most likely due to thinking I should need one!

[vlodjak]

Does anyone know any tone generator programs on the computer, it would be cool to mess with sound or even edit any famous songs with that kind of frequency. Thanks

[Anthony]

Cooledit has a tone generator.

Myrol, please post some evidence that this works. Who tested it, with what equipment, and what were the results.

I just tried it myself and the results were as expected - nothing! I used the tone generator in Cooledit, my PC onboard soundcard, a technics stero amp and wharfedale 100W RMS speakers.

The first problem is the high frequency - the upper limit for human hearing as ~20KHz, and that's being optimistic. Most audio equipment will not respond to frequencies above 20KHz. And you won't know if it is or not, as you can't hear it.

Secondly, these "sound weapons" usually require high power levels. E.g 100W at 1 metre. In theory, my amplifier and speakers can fulfill this. However, the bass driver is what delivers the vast majority of that power. At 22725Hz only a tweeter will operate, and they don't deliver much in the way of wattage!

As I remember, the thread years ago about low frequencies causing death in humans was closed because of a lot of "I heard..." and no concrete information. Or even mildy firm mud...

EDIT: I did perform the test t -30db, although I have no idea why this is required. It only affects the "loudness" of the audio (0db being highest). It gives music dynamic range, but for a monotone, I see no point.

[Jacks Complete]

Spot the delibrate mistake - 22KHz is ULTRAsound, not INFRAsound. The "brown noise" idea refers to high powered sound, but INFRAsound. I think it should be 22.725Hz?

The basic idea is that it resonates your bowels... sounds like shit to me.

[kingspaz]

Second test conducted. No effect. I will try it again in a couple of days when I have speakers available which will generate low frequencies properly, and have a much higher wattage. IMO this is bullshit though, so I'm hoping to prove it wrong!

[zeocrash]

I've been trying with my new pc speakers (creative gigaworks, 700w). I haven't had any luck with giving myself the shits or puking or what have you, but i have found the resonant frequency of my computer room and my computer desk :)

[Jacks Complete]

IIRC, the sound pressure levels were high enough to be nearly fatal anyway. The only reason to tune it that low is so the target cannot hear it, unless this stuff about resonant frequencies of the gut is to be belived (I don't. Simply tense a few muscles and the resonant frequencies all change too, or eat something)

The other issue is that the low frequency sound is non-directional. This means it affects everyone, operator and target, equally (or the operator worse, since he is closer!). I read about someone trying to get directionality out of it using a phased array (much like modern RADAR systems) so it would be useable.

[simply RED]

Very much problems with this physio-psychotronics.
Nothing seems ot work.

Electronic gadgets, ultra, infra, micro... bullsit.
Other problem is the lack of equipment for full tests.

[tdog49]

Saw this on a Discovery Channel show about riot-dispersing weapons. They had stuff like paintballs filled w/ pepper spray and/or skunk perfume, wireless tasers and of course a "brown noise" gun. The model they were demonstrating was big. Vehicle mounted if I remember correctly( I imagine the sound emitter would have to be quite large to be effective) The intended result was severe nausea and disorientation with eventual (not immediate) vomiting or diarreah. This was about 2-3 yeas ago....

Discovery Channel is usually pretty good about legit (if scarce) info, although I have seen programs that I thought were questionable.....

[Jacks Complete]

The brown noise thing requires large things because generating low frequencies means large openings, generally. You also need massive power levels - 10dB is the limit of what you can hear, and is 0.00000000001W m-2. At 120dB, the human (hearing) pain limit, the power level is 1W m-2. For every ten dB increase, the power goes up by 10 times (log scale) and the effective "brown noise" range is supposed to be from 140dB upwards. That is 100 watts per square meter of incident power!

Remember you are fighting against the square law as regards range, too. Sound pressure levels this high break things - they are used for acoustic fatigue tests for airplanes, for example - so it isn't a surprise that people start to feel weird. If you could hear it, you would be deaf instantly. (Ok, in the time it took you to get your hands to your ears!)

You can't do anything clever like beaming the sound without a huge dish, either, as lamda * f = Velocity of wave, meaning that when you are using a wavelength of 22Hz sound, you get a wavelength of about 33cm. This means you need a dish at least 1 meter across to get any kind of directional effect, and the crowd would be sure to notice. There are all sorts of issues trying to reflect that sort of sound power at such low wavelengths, too, since the whole dish will resonate.

Anyway, I'll post more later.

[spat]

Using something other than "classic" acoustic techniques.

What happens if you electrically detonate a series of explosions at the proper time delay. It wouldn't be a sine wave but it would have alot of power :)

Or, what happens if you detonate a series of explosives simultaneously but have them spaced properly in a line (1 wavelength seperation) Would this produce a directional sound wave ???

The explosives need not be hard to obtain high explosives, it seems like a briggs and stratton 5HP engine running under load at the appropriate rpm would produce the sound. You could design an exhaust system to adjust the waveform and reduce the higher frequencies if necessary.