The Heterodyne Hypothesis

[Guest BFSleuth]

Yeah, that is what I thought.

The time I knowingly listened to infrasound it did sound like a flutter. It was a private concert and lecture given by a young man that was developing his own synthesizer, this is way back in the early 80's. It was pretty cutting edge stuff. I remember he had this awesome set of speakers, and when he talked about and demonstrated the infrasound range those big speaker cones were visibly traveling in and out about 1.5" to 2". It created a feeling of fluttering pressure, like when you crack open only the rear passenger window a few inches in a sedan at 50 mph (each car will be "tuned" differently).

The video I posted above seems to have a higher tone that oscillates at 12 hz. It was the best of the lot when I tried to search for 12 hz that might come close to what is being described as heterodyne effect.

As a side note, gorillas beat their chests up to 10 bpm quite loudly. Folks that have witnessed that up close say they can feel it in their gut, similar to infrasound.

[Guest Prehistoric Fisherman]

Prehistoric fisherman: The non-linear mixing of two frequencies f1 and f2 results in two produced frequencies, f1+f2 and f1-f2. By way of example, mix 10,012 Hz with 10,000 Hz and you get 20,012 Hz and 12 Hz. The 12 Hz is the produced infrasound. You can't hear the sum frequency because it is ultrasonic.

I think that was one of the things I pointed out ("But one of the sub-frequencies might approach the audible range."). So we agree?

And that's how I understood it too, though I wasn't sure if that's what they really meant (i.e., I find the idea somewhat problematic, as applied). By that I mean if you have any two frequencies that are really close together you would get infrasound as one of the products (which would imply its really easy to produce, the issue of amplitude being the only unknown issue), and I suppose any two moderate frequencies would produce another of really high frequency (for each example I'm ignoring one of the new products, for clarity of each point). Why don't the two new frequencies produce their own new heterodyning offspring (I mean, their just frequencies, so why not) in an infinite cascade? If they did things would get messy real fast, even if amplitude decreases every time. So I guess my next question would be whether signals heterodyne during all circumstances, or whether its a rare event, or whether its as common in audio frequencies as RF (assuming it is common in RF)? My best guess is that if heterodying is occuring in acoustic data then there is a massive drop-off in amplitude and essentially it appears unnoticible. To put it another way, I've never noticed it in my recordings.

Are you saying that ultrasound is producing infrasound through heterodyning and the infrasound is what is causing the fluttering?

But I guess my original question for you boils down to: in your theory is the fluttering due to the inconstancy of the signal (modulation of some form), or because of the new products of the hetrodyne signals, or both? It sounds like originally you were saying both, and my proposal is that regardless of whether its infrasound or ultrasound the fluttering is being caused because its not a steady tone (fluctuation in pressure waves) or wave motion (I'm blanking on words, its been a long day). If the latter, it might point towards infrasound as the culprit because the cycles effecting the ear would be relatively low (say 8-20 times a second) whereas with ultrasound they would be very high (i.e., cycling fast, and probably seem more or less constant in to the perceiver).

BFSleuth: > Any thoughts that the current outbreak of booming sounds in Clintonville, WI might be infrasound? Seismometers aren't picking it up and they've ruled out any gas leaks or other issues. <

Official word is that the govt seismologists have picked up one or more quakes. They insist (according to TV reports) that they can't be felt by the populance. The town administrator had a televised meeting and claimed the granite (?) in the area is just right for transfering the shocks and that's why they are being felt. I have no explanation as to why the govt. scientists don't know about that. Public comments included the question as to why the same sounds were being heard at the same time for four mornings, which doesn't sound very seismic to me.

I have considered going there to see what I think, but I hate to submit myself to too much wild goose chasing (its well over a 4 hour drive). Do any of the reports sound particularly like tree-knocks? I've heard very loud knocks, which I compare to typical Civil War re-enactment cannons, which I presume are 2-3" pieces (from what little I remember). The TV reports here are pretty vague as to what is actually happening.

That houses are shaking doesn't sound very BF-related to me (unless he's shaking them one at a time). On the other hand, if events are synchronized to our clocks to any extent that doesn't sound very seismic.

Did I mention its been a long day? Apologies for the spelling errors above, I don't have the energy to track down the corrections.

Edited March 23, 2012 by Prehistoric Fisherman

[Guest]

Years ago I came across a article telling how the French military were experimenting with infrasound as a weapon. My recent search (Google)

uncovered a paper with similar information "Acoustic Trauma: The Bio-effects of Sound†http://www.schizopho...hesis/index.htm.

â€Frequencies corresponding to the Alpha, Beta and Theta brain rhythms have been utilized in similar manners to influence neural activity.

This is perhaps why the fabled infrasound frequency of 7 Hz is so notorious as it is the median frequency of the brain’s theta rhythms.

This frequency is most prominently associated with moods concerned with fear and anger. It is also allegedly the average resonant

frequency of the body’s organs and hence excitation would cause organ rupture and death.â€

[Guest Prehistoric Fisherman]

I don't have the speakers to be able to hear this very well. Anyone else try this?

http://www.youtube.com/watch?v=XrpGcvmlohk

Using laptop speakers there was zero effect (the same should hold true for most headphones, as the speakers are too small to do low frequency well). Using the cheaper but moderate sized "gaming" speakers (with subwoofer) attached to a desktop system at maximum volume with the base turned all the way up was quite a bit different. What seemed to happen was that my forehead -- or maybe my face from the cheekbones up -- (including my eyes) seemed to be vibrating. At least that was the sensation I received, which surprised me so much the first time I couldn't quite figure out what was going on. I played it three times to be sure I was understanding what I was feeling. Within a few minutes I started to have a mild, but persistent, headache. There was also sudden but mild nausea. Possibly this was coincidental but the timing was interesting. One possibility is that the effect was limited to the top part of my head because of speaker placement, particularly the subwoofer, as there was a barrier blocking the rest of my body.

I didn't really expect as blatant a physical reaction. I'm not really sure what would happen if my large speakers and stereo receiver had been used with the base turned up (the speakers are in storage, so maybe I got lucky). I don't recommend anyone try playing this with a powerful speakers system at maximum. Start lower and increase incrementally would be my recommendation.

Is the vibrating sensation merely pressure waves on the surface of the skin or a penetrating vibration? Well, if I repeat the procedure and get another headache, I would have to at least suspect the latter. I guess I'll refrain from further comments until I get a chance to try again.

BFSleuth, I take it this wasn't your recording? I remember someone on the old board claiming they were nearly knocked out by a BF sound, but if I remember right he was in Michigan and this clip seems to be from Canada. With the clip out of context its hard to evaluate its origin.

[Guest BFSleuth]

prehistoric fisherman, thank you for taking the time to run through your experiment. I don't have ready access to a speaker system that can give that kind of output. I found the video on the internet, not one that I created. Very interesting observations. Now you've got me revved up to go and try to find a speaker system!....

[Guest]

Using laptop speakers there was zero effect (the same should hold true for most headphones, as the speakers are too small to do low frequency well). Using the cheaper but moderate sized "gaming" speakers (with subwoofer) attached to a desktop system at maximum volume with the base turned all the way up was quite a bit different. What seemed to happen was that my forehead -- or maybe my face from the cheekbones up -- (including my eyes) seemed to be vibrating. At least that was the sensation I received, which surprised me so much the first time I couldn't quite figure out what was going on. I played it three times to be sure I was understanding what I was feeling. Within a few minutes I started to have a mild, but persistent, headache. There was also sudden but mild nausea. Possibly this was coincidental but the timing was interesting. One possibility is that the effect was limited to the top part of my head because of speaker placement, particularly the subwoofer, as there was a barrier blocking the rest of my body.

I didn't really expect as blatant a physical reaction. I'm not really sure what would happen if my large speakers and stereo receiver had been used with the base turned up (the speakers are in storage, so maybe I got lucky). I don't recommend anyone try playing this with a powerful speakers system at maximum. Start lower and increase incrementally would be my recommendation.

Is the vibrating sensation merely pressure waves on the surface of the skin or a penetrating vibration? Well, if I repeat the procedure and get another headache, I would have to at least suspect the latter. I guess I'll refrain from further comments until I get a chance to try again.

BFSleuth, I take it this wasn't your recording? I remember someone on the old board claiming they were nearly knocked out by a BF sound, but if I remember right he was in Michigan and this clip seems to be from Canada. With the clip out of context its hard to evaluate its origin.

I won’t pretend to be some sort of expert in bioacoustics but I don’t think

the potential for vibration-induced physical or physiological problems is being

sufficiently emphasized here. When an opera singer sings a note whose frequency

matches the resonant frequency of a crystal glass, the glass shatters. The human body

and its parts each have their own resonant frequencies. When subject to frequencies less

than 20Hz (the lower limit of human audition) bad things can happen. Symptoms can

occur and may range from headaches to drowsiness to actual tissue damage. This is

because if an external frequency coincides with the resonance frequency of a body part,

the resulting resonance becomes a multiple of the original, natural frequency which, in

turn, may be hazardous to your health.

That is why we have standards under The International Organization for Standardization

(ISO) for mechanical vibration and shock – evaluation of human exposure to whole-body

vibration (ISO-2631 Part 5). And we teach about it in ergonomics courses:

http://ergo.human.cornell.edu/studentdownloads/DEA3500pdfs/Whole- BodyVibration.pdf

RE

[Guest spurfoot]

I would like to take time out to point out that this entire thread is an example of how Bigfootforums should be working. All we have here are helpful cooperative comments working toward a common goal of trying to understanding the alleged BF zapping phenomenon.

It is irrelevant that the various comments are entertaining both actual infrasound and perceived infrasound (or fluttering) via heterodyning. The main thing is we are contributing usefully. Compare this to the sniping and "harping" going on on other threads. Good work guys and gals. Keep it up.

[Doc Holliday]

yes,spurfoot this has been a pleasant one so far.

helpful hints,suggestions & a little humor here & there make for a good thread, imo.

so if yall see an "infrasound cryptid attraction device" for sale on ebay, then youll know where the idea came from

[Spader]

Can the Semi-Circular canals be affected by this?

[bipedalist]

Yes, there are vestibular effects reported in the literature along with vertigo and disorientation..... you'd basically loose your balance and hurl like you were seasick if the frequencies were just right..... the shaking, bouncing, juddery eyeballs that PF reported upthread a case in point.

[Guest BFSleuth]

I would encourage folks to Google "Cymatics" sometime.

It is the study of visuals of sound. Certain wavelengths produce different patterns. Some wavelengths will create standing waves like this:

http://www.youtube.com/watch?v=63swuFp5-xc

At 14 hz the standing wave looks like this:

I've read that at around 18 hz is when people have visual hallucinations or grey spots start to appear. Note that the 14 hz waves start approximating the size of an eye. If an eyeball starts vibrating as in the video (remember it is liquid filled) then I could understand how that would disrupt your vision.

Imagine standing waves impacting your body at frequencies that approximate the size of your chest cavity or major organs. At 4 hz to 7 hz really bad things can happen, depending on the volume.

If BF have this kind of capability, then they probably use it for hunting or when threatened, like a tiger or lion.

[Guest Prehistoric Fisherman]

I would like to take time out to point out that this entire thread is an example of how Bigfootforums should be working. All we have here are helpful cooperative comments working toward a common goal of trying to understanding the alleged BF zapping phenomenon.

It is irrelevant that the various comments are entertaining both actual infrasound and perceived infrasound (or fluttering) via heterodyning. The main thing is we are contributing usefully. Compare this to the sniping and "harping" going on on other threads. Good work guys and gals. Keep it up.

Thank you Spurfoot, I was concerned that it might seem like I was trying to dominate the conversation, which is not my intention. I wouldn't like to be like the 800lb gorilla in the room (despite any resemblance). I find the hypothesis you present interesting in several different ways and have just been trying to ferret out its details, and my training tends to make me rigorously examine all possibilities. One way of looking at theories is that they can never be proved (there can always be an alternative explanation 'just around the next corner') but only disproved. While a theory may or may not pass the test of time, in the here and now I prefer to make a maximum effort to see if they seem "air tight" here and now. So I apologize if I seem like I'm badgering, I'm just attempting a bit of a shakedown cruise, so to speak.

I too have enjoyed that the participants are all trying to be useful, and wish all discussions could be that way, whatever the personal views of the participants

prehistoric fisherman, thank you for taking the time to run through your experiment. I don't have ready access to a speaker system that can give that kind of output. I found the video on the internet, not one that I created. Very interesting observations. Now you've got me revved up to go and try to find a speaker system!....

No thanks are necessary. I feel the need to point out that, at least in my case, we don't know the actual origin or conditions in which this was made. I suppose the story is out there somewhere and with some effort it can be tracked down. I don't assume that this or similar recordings are fabricated. As someone who makes audio recordings myself I am well aware that as evidence to prove anything they are fairly useless. If one believes the recording is 'on-the-level' they can be studied, but to the outside observer there is always an unacceptable level of uncertainty as to the veracity of any piece of indirect evidence. My own efforts are mainly to document what happens, and to be used for later analysis (if possible).

In this case, we do (I believe) have infrasound. I haven't looked at it in an audio editor yet, but the effect was interesting enough that this is what I expect to find. Now there are man-made and natural sources of infrasound, so I'm not sure entirely what this is. To me the recording sounds very noisy, and its not clear at this point what the context is. Having a longer recording, particularly one where "nothing" is being recorded for several seconds (i.e., just background noise) would be necessary for me to have much of a clue as to what is going on. Is the additional "noise" part of a BF sound, or is it just environmental noise, or is it self-noise of the recording equipment, or a combination? Without an unaltered copy its hard for me to say.

I would guess that in the process of getting to Youtube it may have been encoded several times with lossy formats, and information has been degraded. I'm not sure that this particular recording is useful as an infrasound "BF Call". After my own experiment with it I have to say it is tempting to use it as such and see if it gets results. My own situation is that I often get responses to audible signals, so if I only use infrasound and I get a response, and if at a later date I can replicate that result again, that would be an interesting finding. So I may make an effort to do so at a later date. The recommended procedure would be to try to put some sort of acoustic shielding on the "back side" of the emitters to try to shield the effect on the users, wear professional sound protection, to keep as far away from the speakers as possible while broadcasting and never to go in front of them, to only emit infrasound for a few seconds, to only repeat that a few times, and then to quit and wait for the results. See the response to the next poster for why exceeding these guidelines would be bad. Additionally, I can't say that what I recommend above is safe, its just minimizing the danger.

The other thing is that, being constructed similar to human beings but on a larger and tougher scale, BF would presumably be vulnerable to some or all of the effects of the infrasound. Using it on them at close range would most likely either drive them off or be considered an attempted attack. They would likely be much more aware of the phenomena than we are and would react considerably faster to it as a potential danger.

I won’t pretend to be some sort of expert in bioacoustics but I don’t think

the potential for vibration-induced physical or physiological problems is being

sufficiently emphasized here.

I agree entirely. I was very surprised by the results of the experiment, as the physical effects though somewhat subtle were immediate. Playing around with sound is not a safe activity. I have experienced hearing loss of unknown origin over the course of my life. Whatever has caused it the result is unusual and puzzling to the specialists. While much of my hearing is intact, some frequency ranges have been obliterated. In addition to this, there have been some BF related activities on my part that have made it worse. In my effort to use parabolic mics with headphones, additional damage to my hearing has been done. No matter how careful one is, while in the field eventually your arm will move to close to the headphones and feedback will occur. Despite the fact that the device I was using had "safety cutoffs" in case of feedback these were not designed properly and kicked in far too late, and as a consequence (after about four such incidents) I believe I have lost quite a bit more of my hearing. That's one reason I adamantly don't recommend monitoring hand-held audio in the field (among others). Additionally, in my initial experiments with game calling equipment I think some additional damage was done, because I underestimated the danger. The sounds being emitted didn't seem very loud (compared to myself, for example), so I didn't see it as dangerous and stayed too close to the speaker and used it far too much at various locations. It was only after returning home that the pain and ringing began, and with it went another small chunk of my hearing. If I use it again I'll have some hearing protection and play out the speaker wire to its maximum length. Once your hearing is gone you are not getting it back, and if you have the additional 'benefit' of permanent ringing in the ears your quality of life is going to decrease radically as well. Again, there are no effective treatments for hearing loss of this type, and it can happen to you before you realize anything is going on.

Infrasound is even more dangerous because it is hard for humans to detect at all. Hearing damage is a strong possibility, if only because one can't judge the loudness at all. With significant volume physical damage to the body is quite possible, including preventing breathing, organ damage, and other structural damage on a large scale that could be impossible for a doctor to treat effectively, if only because there is no training for treating such injuries taught anywhere in to world, to the best of my knowledge. It would probably be safer to play around childishly with a shotgun than to do so with really significant infrasound. You probably wouldn't point the shotgun at your face, for example, as I did with that infrasound sample...

so if yall see an "infrasound cryptid attraction device" for sale on ebay, then youll know where the idea came from

Hey, patent pending...

Yes, there are vestibular effects reported in the literature along with vertigo and disorientation..... you'd basically loose your balance and hurl like you were seasick if the frequencies were just right..... the shaking, bouncing, juddery eyeballs that PF reported upthread a case in point.

Yeah, it wasn't so much that my vision was bouncing in this case, but it felt like my eyes or eyelids was gently but quickly being vibrated, along with a large chunk of my head. It was a bit like standing in front of a very powerful fan and feeling the passage of the blades, but without the associated airflow it was at the same time more like a vibrating effect from some device, just somewhat localized. Once the headache started I was concerned that more critical damage had been done. Does it seem like I've lost IQ points?

I've read that at around 18 hz is when people have visual hallucinations or grey spots start to appear. Note that the 14 hz waves start approximating the size of an eye. If an eyeball starts vibrating as in the video (remember it is liquid filled) then I could understand how that would disrupt your vision.

Imagine standing waves impacting your body at frequencies that approximate the size of your chest cavity or major organs. At 4 hz to 7 hz really bad things can happen, depending on the volume.

If BF have this kind of capability, then they probably use it for hunting or when threatened, like a tiger or lion.

I tend to look at there use from a minimal rather than maximal approach. If they can use infrasound to cause fear, several of them can use this in concert to drive animals into a trap, panicking them enough that they ignore BF scent for example (which, in my experience, would be a major detriment since it can be extremely powerful). The prey are 'beat' using Infrasound as a moderate range stimulus towards the trap, which would be one or more individuals that kill at shorter range, possibly using audible and infrasound to startle the prey into being immobile at the moment of killing. This is conjecture, as I'm not sure we have cases of this being done, and the default 'scientific' model provided by Krantz's footprint study seems to imply a more solitary existence (I seem to be detecting quite the opposite).

Its possible that the infrasound is more powerful and effective (the more extreme claims), but at a minimum it seems likely that what I describe above is possible for them to do, the advantage over tigers being that they are more intelligent, understand their capabilities better, and can work as a team.

Edited March 28, 2012 by Prehistoric Fisherman

[bipedalist]

Well, actually there could be two effects operating on the juddery eyes, both effecting/affecting vision...... according to this study nystagmus could also be an explanation as a result of vestibular overstim.

http://www.ncbi.nlm....pubmed/18706484

http://www.ncbi.nlm....pubmed/17300889

http://www.ncbi.nlm.nih.gov/pubmed/17014895

Edited March 28, 2012 by bipedalist

[Guest]

A digital recorder can go all the way down to zero hertz, i.e. DC. The limitations of commercially available recorders are only because they have a high pass filter on them so that they only record stuff higher than 16 Hz or so. That filter can be disabled or modified. I suggest modifying it so it passes stuff above 3 Hz or so.

The only real low frequency limitation in the total recording process is the sensor, that is the "microphone" , attached to the recorder. A low frequency microphone must be physically large, just as a low frequency emitter must also be large. Think ultra large "woofer" from your hi-fi. I have sometimes thought of simply using a large plate of styrofoam with styrofoam ribs glued on for stiffness. Balsa wood would also work. The movement of the plate must then be coupled with a movement transducer that is then attached to the digital recorder. Obviously, low frequency capability means unavoidable sensitivity to wind.

Office Depot and similar stores sell 1/4 inch styrofoam for science fair displays. The movement transducer could be a LVDT. You can easily build one yourself.

Detecting infrasound -

There are lots of good pointers and resources in this thread. I like the one above, notably because it's cheap (like me). And here's another one

http://www.infiltec.com/Infrasound@home/

Note the application :

• Alleged haunted site or ghost monitoring.
  

Might be good for Bigfoot, then, regardless if BF is real or not.

RE

[Guest Prehistoric Fisherman]

Well, actually there could be two effects operating on the juddery eyes, both effecting/affecting vision...... according to this study nystagmus could also be an explanation as a result of vestibular overstim.

It is indeed an important point, thank you for making it: "The vestibulo-ocular reflex needs to be fast: for clear vision, head movement must be compensated almost immediately; otherwise, vision corresponds to a photograph taken with a shaky hand." ( http://en.wikipedia.org/wiki/Vestibulo-ocular_reflex ) So, if Infrasound disrupts this reflex its a second way to degrade the ability to see, along with direct vibratory resonance to the eyeball itself (at least at 18Hz).

This is what I meant about explaining cases which would be labeled moderate to high strangeness (i.e., the seeming default explanation is labeled 'paranormal' since it seems to lack a conventional explanation). In short, if you have a cyptic being operating usually in darkness which can emit sufficient infrasound that it can (at least momentarily) disrupt vision combined with (a rarely, but consistently) reported ability to leap 25-30 feet at a time, the end result is that you have a plausible naturalistic explanation of something which at first seems so mysterious as to be supernatural. Similarly, the ability to leap such great distances (along with backtracking, obviously) would likely explain the cases of a series of tracks ending mysteriously with no sign of where their maker went. Such cases are rare, but in general they are ignored because they have the taint of alleged paranormal abilities. In either case, the paranormal explanation of dematerialization or invisibility are unnecessary, particularly if one combines the reported agility and ability to hide (be cryptic) along with an infrasound capability. The neurological and psychological effects of infrasound go a long way towards explaining other cases (fear without apparent cause, paralysis, animal silence, etc.) which are reported both in modern times and native legend. Back on the old board I seem to remember Tirademan providing some vintage clippings detailing native american legends regarding unusual BF abilities, perhaps if he is monitoring this thread he may have a comment.

http://en.wikipedia.org/wiki/Fear_liath

http://cryptozoo.monstrous.com/bigfoot_powers.htm

http://www.sunstar-solutions.com/BFvanishing.htm

(provided as examples of such claims).

Now I realize that I am skirting the line that was established on the old board, that discussion of these type of claims was inappropriate -- and as I understand it banned. I hope that providing a naturalistic explanation for some of these claims -- one that seems well within what BF reports and animal research have separately documented -- is seen in a different light. If discussion along these lines is inappropriate hopefully the moderators will let us know. If anyone has a contradicting rebuttal to my argument (i.e., someone supporting the 'BF is paranormal' theory), you might want to ask a moderator first if your line of discussion is appropriate.

Detecting infrasound -

There are lots of good pointers and resources in this thread. I like the one above, notably because it's cheap (like me). And here's another one

http://www.infiltec....nfrasound@home/

Note the application :

• Alleged haunted site or ghost monitoring.
  

Might be good for Bigfoot, then, regardless if BF is real or not.

RE

Yeah, I kind of wondered when if I mentioned geophones earlier whether the topic was dropped from discussion because I suggested searching for "ghost geophone". Its just that in terms of consumer use of such a device there are few other applications. Its not like a geophone is going to help the average Joe's golf game. I want to be clear that I'm not advocating that investigating BF is directly related to ghost hunting (other than that Skeptics and Believers lump all such fringe 'science' together as 'paranormal'), just that there are overlaps between the two fields for possibly useful equipment.

As to the page you provided it does seem to be chock full of links, good catch. The price seems a bit high to me, but perhaps the "consumer" equipment targeted at "ghost hunting" isn't as high of quality.