Similar to Long-range Acoustic Devices (LRADs) there is a weapon floating around that emits within the audible high-frequency range more than likely used by either law enforcement or espionage in particular within areas with extremely high corruption that does not seem to be as documented as an LRAD but given the many complaints it is a device that is worth documenting. With that being said, the weapon is documented in terms of observation, intent and effects, with accessible counter-measures being offered that can be built using household items.

These devices might be prevalent in "make-belief democracies" that are just more or less thugopolies such as countries in Eastern Europe like Romania where the powers within the state are blended together and the police cooperates with organized crime to the tune of better mixed-legal outcomes for everyone with with minimal oversight from regulatory organizations like the European Community that functionally just bribe these countries to be left alone. These are also political areas where you'd expect the state to play dumb or "accidentally" funnel weaponry like NATO weaponry to organized crime for the purpose of maintaining order via a proxy that would also convey some plausible deniability in case the perpetrators are caught. Even our own speculation on what these devices are for as will be documented further on is that such devices are designed as pacifiers for terrorists that probably given the weakness of the country are then just used by various gangs of the state to discredit or subdue potential political actors or used in an attempt to steer people with particular qualities (and for these decrepit countries, just being able to add two numbers together classifies a person as "highly intelligent" or a potential country-wide expert). These are also regions where the powers of the state are blended together unappologetically and where "rule by mob" is ironically a virtue rather than an undesired polarization such that you might find perpetrators ranging from medical doctors to the police and along with common street thugs that would participate in these schemes. Either way, too much talk on geopolitics is fairly trite given that such regions of the Earth have never amounted to anything in the past, with these countries being the proverbial bottom of the barrel cleanly across all country metrics socially, civically, scientifically etc., such that dwelling on the particular reason why these measures are employed is a colossal waste of time. It is also the reason why this writeup is presented in a non-alarming way and with defensive solutions rather than offensive because more than likely the operator is just some expendable that works by proxy and is of little worth even if caught. These are also states with Soviet-style anti-rational inversions, with people that have demonstrable results and proven track records that should have ended up filthy rich elsewhere, end up poor, and conversely criminals or thugs that shouldn't even be part of society in the sense that they should be in jail, let alone poor, being counter-intuitively rich and powerful, with these results obtained due to the state manipulating reality using both legal and illicit means which leads to these "mutant" results in terms of organicity. Aside the politics, claims from these countries whether in terms of justice, security, science or most other domains should be taken lightheartedly (at best mocked and dismissed), given that these are collectivist countries with wide range of participants that have historically low results such that taking them seriously requires "belief" and propaganda.

Nevertheless it is worth mentioning where such devices might be used the most, in terms of incidents and it seems clear that there are specific preconditions of corruption and state ineptitude that facilitate the misuse of such devices.

The sound is felt as a barely-audible pulse, somewhere in the upper-audible range, perhaps due to the properties of higher frequencies being capable of passing through objects much better than lower-frequencies. At the same time, the high-pitched pulse seems to be workable even for various degrees of hearing impairment, perhaps even being able to work for people with a complete hearing impairment due to the high-pitched pulse that might be interpreted and conduced by the subject via the bones of their skull (so, shaving your ear off is not an option).

In relatable terms, perhaps the closest resemblance of the noise would be a TV screen white-noise, but not in continuous form like detuning a TV, but rather as a small quarter or half-second pulse. Compared to an LRAD that typically would have the purpose of scaring away subjects with a high volume, the noise produced by this weapon is on the contrary fairly low and more or less tuned to the hearing capacity of the subject.

People reporting these noises also incidentally state that they have extremely good hearing and one possible class of perpetrators could be medical staff that examine people either for work, or children at school and then document their hearing capabilities or report them to the security services. One case in particular stood out with one individual reporting a clear memory when they were on a routine medical examination while being at school where the examining doctor even ostensibly expressed her admiration for the good hearing that the pupil had.

Similar to an LRAD, the device seems to be mainly a pacifier, used as a training tool with feedback based on Pavlovian principles that is meant to steer a subject and influence their decisions. The psychological principle seems very simple, it is no more advanced than a shock collar for animals or a cattleprod and with the intent of changing a subject's behavioral pattern.

The device emits a short noise burst or a series of noise bursts and can easily be distinguished from random noise given that the noises in terms of intensity that are produced by the weapon differ contextually between the activities of the subject. For example, when a subject performs a certain activity, the weapon is used to some level compared to a different activity that the subject is meant to be deterred away from.

With the former established, it seems implicit that the device is used by an operator that has a certain degree of observability into the subjects life, for instance, with the help of more standard spy equipment such as a microphone or maybe even a visual feed using cameras, which given the contextual differences seems necessary such that the operator knows when to emit the noises or not depending on the subject's activity.

With that being said, it seems clear that this weapon is both a deterrent and an espionage tool that invariably leaks irrepudiable private data and more or less a violation of the law or judicial procedures in most jurisdictions. It might be the case that the weapon was meant to be used against terrorists in order to act as a deterrent when the subject has been previously clearly been established as a terrorist but there is a lack of material to be able to prosecute them.

The device itself might cause nausea but only in terms of excessive usage but compared to an LRAD it seems to be less of an offensive device and more of a behavior or training device that is meant to alter behaviors.

Historically, perhaps as a cover-up, the weapon is easily confused with a misdiagnosis of a condition called "Tinnitus" or a "hissing of the ears" that is clinically due to ear damage. The cover stands fairly well, given that newer generations listen to music a lot of the time and because the symptoms are identical. However, the existence of the weapon is distinguishable from the medical condition "Tinnitus" by observing that the weapon will be used by an operator to encourage or dissuade a very specific behavior, let's say, playing computer games, such that a subject might end up being bombarded with pulses when they're playing games but not when performing any other activity, such as eating or sleeping. The former is then contrasted with the medical condition "Tinnitus" that is identical in terms of symptoms but by comparison does not discriminate between activities and is rather a continuous stream of hissing in the ears of the person suffering from the actual medical condition.

Medical staff that are perpetrators and are participating in the scheme might pretend that they do not understand why the noise intensity varies by activity or might try to justify it by stating that different positions of the body or maybe different environments will change the behavior "Tinnitus". However, most case suggest that the environment is a static variable and after a certain amount of time it becomes observable that the noises vary with activity rather than with the architecture. However, one must bear in mind that like any other weapon, the device is beholden to the rules of physics such that different environments do indeed change the intensity, maybe depending on the permeability of the environment.

Based on observation, people report that deep underground tunnels will seemingly block out the weapon, although that is not sure whether that is to be attributed to "echo-chamber" properties or whether the signal is actually emitted above ground or perhaps even using satellites from space. Another frequent property that seems to corroborate the stories is that subjects report that being in motion will greatly decrease the intensity of the noises up to reducing them completely to zero. Some even state that it feels like the weapon is somehow trying to acquire a lock but is not managing to adapt fast enough to the movement of the subject. Then, when the vehicle comes to a standstill, the intensity is restored.

Otherwise, it seems that surrounding electronic devices do influence the noise intensity but the electronic devices seem to act more like "amplifiers" than generators and even cast a shade of doubt on whether the noise variation with electronic devices switched on or off is more of a parasympathetic bias that alters the environment such that the weapon has to be re-calibrated by the operator rather than the surrounding electronic devices themselves having any particular role. For instance, an individual with a troubled mind, so to say, might end up self-hypnotizing themselves and tuning themselves to the environment such that certain noises that occur will be perceived by the subjects much louder than they really are.

Another component does seem to be geometry; for instance, sitting on a couch in a certain way might make the noises way more audible than being in a different area and most of that is more than likely attributable to physical shortcomings of the weapon technology where different environmental obstacles have the tendency of blocking or blurring out the noises.

Eerily the weapon usage seems unbelievably widespread with lots and lots of reports of "Tinnitus" that could not really be explained in terms of any medical evolution of human beings. For instance, it seems that there is a boon of papers after the 1960s studying Tinnitus with an ever-increasing amount of cases that does not seems to be too justified in terms of organicity. Some of the statistics are more than likely biased in terms of medical observability and reporting over time that might make the statistics increase just due to people being more forward with reporting their medical condition by seeing a doctor. Nevertheless there is also a steady increase in the age groups, in particular younger age groups that report "Tinnitus" more than before, that also does not seem to be justified too well given that "Tinnitus" is mostly reported by people above the age of 60 and much more compared to younger ages.

Ironically, regardless of the science, certain sleeping-aids devices seemed to have mysteriously appeared modernly and given a lot of attention, along with lots and lots of reports from people claiming that they need "sleeping aids", autonomous sensory meridian response ("ASMR") or other parasympathetic technologies just to manage to relax or fall asleep. The former is often justified by medics in terms of generalized stress (and for sure, vastly misdiagnosed as Schizophrenia probably due to the disbelief or unreliability of the examiner), and whilst stress is indeed a mood changer, it would be very rare that stress alone would trigger outright hallucinations in a very very large population that is otherwise very socially and civically functional.

For example, there is a sharp emergence of "sleeping headphones" that are designed to be worn while attempting to fall asleep that have some built-in memory and will resort to playing back various "ASMR" tunes, like waterfalls, rain or melancholic music that helps the body slide into sleep. The reviews on such devices, just taken by the sheer quantity alone is baffling making it seems as if "Tinnitus" is rather some "plague" rather than some unexplained medical condition studied since the 1960s, with hundreds upon hundreds of users sharing their experience with the "sleeping headphones" as well as their story on how they work for them. From time to time, within those reviews, you can find stories that do not resemble "Tinnitus" but would rather indicate the usage of the weapon described above, in particular due to the person writing the review claiming that there are massive contextual differences when the noises occur that seem to vary more with the individual's activity rather than being one constant stream of hissing noise as reported by people that actually have the "Tinnitus" condition.

Lastly, the use of psychotropic drugs, even if prescribed by a doctor should really be limited to emergencies or personal emergencies because their usage in context is silly. First, the drugs will sedate the victim instead of doing anything to the operator and it would be a more sane solution to find the operator and hold them responsible. Second, and here's the cookie cutter, psychotropic drugs have the side-effect of rendering the subject even more suggestible such that the task of the operator is made even easier if the subject is under the effect of drugs.

It takes a certain amount of self-awareness and focus to determine that first, the noise is present and second, that the noise is contextualized by activity. When under suspicion, a simple exercise is to go about the day normally, performing various activities while introspectively studying the noise patterns and determining when they seem to have a deterring effect that can be linked to a certain activity in particular. Keeping in mind that the purpose of the device is to change behavior, there will be certain activities that an operator would like to discourage and certain activities that an operator would like to encourage. One individual reported, as an example, that the harassment subsided when they would play computer games, but would accentuate when they would try to get some work done, with this pattern being repeatably observable just by working and playing while being attentive to any noises. One other technique is to move to a different area and then wait and see whether the noises follow shortly thereafter, which would indicate a recalibration phase, like turning a gun around to point at a different place.

Of course, for audio professionals, there might be "industrial" equipment out there, such as a wide-spectrum microphone frequency analyzer that would be able to listen on all frequencies at the same time in order to hopefully read a spike within the upper part of the audible hearing range for humans. However, it does go without saying that such equipment is expensive, and even if a pulse is observed, there is still the lingering problem of burden of proof to prove beyond a reason of a doubt that the pulses are intentional and also have the intent stated in this document. Generally speaking, unless the subject is an acoustic professional, we generally would not recommend going down this route due to the former, as well as the fact that this weapon is easily dispelled otherwise without having to resort to purchasing expensive equipment. Bear in mind that as stated before, the weapon is more than likely used as part of a police and/or espionage operation such that there is more "in the air" than just this "clicker"-device and it is a good policy for the subject to conserve their resources.

More than likely the noise is not measurable with a Software-Defined Radio (SDR) because it clearly must be at least barely audible by a human being, such that investing in such an equipment does not make sense for the study of this weapon in particular. Of course, it is always nice to know what sort of EMI pollution exists around oneself, especially around living quarters where the purpose should be the pinnacle of relaxation but given that an SDR greatly exceeds the audible range, it's usage would not make much sense for the detection and study of this device.

The best way that we have found to suppress this device is to slipstream some noise into the regular material that is being listened to by the subject. The method was derived intuitively off the "age-old" claim of people that report these annoyances and that also claim that listening to noises of "waterfalls" seems to blur out the noise. More than likely due to the speed of water falling at high speed, a waterfall emits noise in the upper-audible spectrum of the human hearing range such that a recording of a waterfall works perfectly for blurring out the noise of the weapon or rather diluting the intent of the noise pulse at a given moment within a pool of similar noises.

In other words, coming back, and after having observed that different activities trigger different noise patterns trying to dissuade or encourage a subject to prefer one action of the other, in case a constant stream of "waterfall" noises are played back, then the pulses emitted by the weapon in different contexts cannot be distinguished in intent anymore. Just pure pedantry, but playing back the waterfall noise has the same effect as joining the contexts together such that it become unclear what action the subject is hinted to when the noise is always the same regardless of the device being used or not.

There are two properties of sounds that seem to be relevant for defeating this weapon and those are the sound intensity (or sound pressure) measured and the actual frequency range being used. Observably, the intensity varies a little depending on the operator using the weapon but the frequency seems pretty fixed to a small range that never seems to slide between some hard-limits.

There seems to be a very nice article "Evaluating water sounds to improve the soundscape of urban areas affected by traffic noise" by Jin You et al. in 2010 ¹⁾ that seems very close to the methodology that will be applied here to defeat the sonic weapon and that seeks to blur out urban noises produced by high-traffic noise pollution like in China by leveraging the noise patterns of natural oscillators like waterfalls or fountains.

The authors explain the "blurring" that we mentioned by using the term masking and make the same argument that the ample noise (in terms of point-density of noise pulses) produced by oscillators such as waterfalls or fountains have the statistical effect of shadowing any noise that is falls within the noise generated by the oscillator such that the noise is then not perceivable by the human subject. We are just going to use the same figure (balled Figure 3 in the article) that the authors offer but it will be cut up an overimposed such that it will offer a quick, dirty and yet effective overview of the actual "masking" that the authors intend to perform.

The blue band (frequency range around the mark) corresponds to the noise produced by falling water and the black band also around the mark represents the noise produced by road traffic. The time and dBA can be used to convert to frequency and the results would indicate that the two noise generators could be made to overlap in terms of intensity and frequency such that playing one on top of the other achieves the masking effect. The authors proceed to explain the methodology through which they started to vary the intensity of the "falling water" noise to the effect of gradually blurring out the road traffic.

Note that the purpose of the article by Jin You et al. is to mask out noise pollution for road traffic and it is important to observe that the road traffic noise takes place unintentionally such that its distress is marked in terms of overall discomfort produced by its abundance but that in terms of defeating this sonic weapon, where the purpose is to trigger noises at opportune moments to change behavior, the blurring or masking of the noises is even more important given that the usage pattern of the weapon is intentional.

Human hearing is said to range from about to about with some peculiarities, for example, the best heard frequency being centered on average at about . However, there are other points that seem interesting in context, given that they represent "peaks" that the ear is capable of distinguishing better than the neighboring sloping frequencies.

There seem to be "inflexion" points at , and that can be marked on the same chart that we are going to label "impressionable" points because these points represent statistical anomalies where a frequency delivered precisely on that point is easier to perceive by a human subject than the rest of the other surrounding points.

The base case is at , which is thoroughly documented, where any sound or noise at is heard much better than any other noise across the whole human audiogram and hence why it is the best heard frequency. However, the other points cannot be excluded because a noise delivered at those frequencies is easier to distinguish from the rest. In layman terms, if a human is listening to a TV show that produces a varied spectra of ups-and-downs in terms of frequency to noise, then if a noise pulse is delivered at , or the noise has a chance to be heard much better over the sound produced by the TV show even at matching noise intensities. In other words, delivering a pulse at should be perceived by a human being much better than a noise pulse at , which might seem strange and counter-intuitive given the assumption of a linear hearing distribution, but it follows immediately from the plot.

To check this theory, an online tone generator can be used that will generate tones at various frequencies, with different intensities (volume) and various sound patterns. It was found that the noise matching the weapon the closest was a , sawtooth pulse played back at a higher volume. Interestingly, we managed to get ahold of an individual that confirmed that this configuration matches the noise that they are perceiving the closest.

With all that in mind, it is clear that the tomfoolery takes place somewhere beyond the mark and perhaps the next-up peak is used at in order to make it a distinguishable noise to the subject of the weapon from the typical baseline hearing mark common to all individuals.

In order to use the same counter-measures as Jin You et al. on masking urban noise, a tone generator could be used that would play back a noise across a frequency range within some headphones, a tone that would be over and up that would then overlay with the regular usage patterns of the headphones. However before devising such a fine-grain blur, we can take a look at noise colors that represent standardized patterns of frequency-to-noise distributions that are conveniently labeled for their typical usage in audio filters.

In essence, we are going to create a band-pass filter, very similar to HAM radio band-pass filters, but a filter that would apply to the human audible range instead. That being said, given that it is known that the weapon noise is located somewhere at , it is desirable to pass all frequencies lower than while blurring or masking all frequencies above, say , with the final resulting aspect of the filter being a slope that starts from the middle of the audible spectre and then slopes up all the way towards the high-end of the audible spectre.

Then, looking at the noise colors, it seems that we'd need a generator that can generate blue noise, or, being more specific, purple noise because those patterns seem to blur our the desired frequencies. In order to see this better, the color noises can be overlaid on top of the human ear frequency response that was shown earlier in order to observe what part of the audible spectre the noise generators would blur out.

With that being said, some blue or purple noise or both of them combined has the highest chance of succeeding to mask this sonic weapon while at the same time having the effect of letting other frequencies pass through. This means that you could watch a movie or even listen to some music with some blue or purple noise overlaid on top in order to not be distracted by the weapon noise.

Most DJing software solutions should work and there are just oh-so-many-variants to playback two or more sounds at the same time. A good and minimalist one is Mixere that can overlay multiple audio tracks and then play them back at the same time synchronized and overlaid. It was chosen to play back both a blue and a purple noise track at the same time for a better coverage of the possible frequencies that could be generated by the weapon.

Note that the frequency-to-intensity plots showing the noise color patterns should rather be interpreted in terms of "shape" rather than frequency-accurate representations and that playing back either blue, purple or a combination thereof should be coupled with the adjustment of the volume in order to find the sweet spot where the setting will work best for blurring out the noise generated by the weapon. The only drawback is mostly habitual, in the sense that it is an extra chore to play back the compound sounds but the method works pretty well to remove most of the suggestions that the weapon operator is trying to confer to the subject.

Otherwise, you can experiment with a digital frequency generator in order to produce some noise that would match the weapon noises even closer simply by varying the frequency and observing what works best at masking the noise whilst also being ideal at passing through the rest of the frequencies. Overall the method is not that great given that the operator is able to change the sound intensity such that the weapon might generate a peak that would be heard over the baseline background noise that is meant to mask the weapon but there are various tweaks possible such as randomly changing the volume of the background noise in order to counter such issues. It is also possible to change the wave shape, which might be more effective at defeating localized sound spikes, but most of the work is done once the frequency of the weapon is determined and from then on out, it's just a matter of optimizations.

We review some of the available hardware that seems to be specific for the purpose of eliminating sleep distractions that also carry value in terms of reducing the weapon noise. Just some examples are shown, mostly because they were reviewd in-shop and we have some hands-on experience with them, but given Chinese manufacturing it is perfectly viable to be able to find something at a fraction of the price that would work just as well or even better.

Just as theorized, the high-frequency noise emitted by the weapon passes right through the ANC on regular headphones, with ironically, the best "ANC mode" for masking the weapon noise being the "transparency" setting where real world noise is mixed with the sound being listened to by the user. This seems due to what ANC accomplishes in terms of "isolation" with ANC being supposed to provide some sense of "focus" to the user by narrowing their audible attention span to the actual sounds being listened to inside the headphones. With the ANC turned to blocking out external noises, this unfortunately generates an attention echo-chamber where the focus of the user is even better at picking out the weapon noise and obsessing over it rather than blocking out or masking the noise in the first place.

Again, this interpretation is lightly advanced and ANC will generally speaking manage to block out the weapon noise but only to some degree, after which, depending on what is being listened to, if the sound has any gaps, the weapon will still be effective at deterring attention or being suggestive relative to the content being watched or listened to.

Otherwise, regular headphones have the only drawback of being too large to be slept on when the subject turns on their side but headphones, in general, combined with a sound mixer are the standard way to blur out the weapon noise. Given that this weapon has also been sensed outside the home, it also makes sense that the headphones should be wireless and portable in order to be worn when needed in all situations. Additionally, at the time of writing, music players like MP3 players are unbelievably cheap due to Chinese manufacturing quantities such that the user has a very large choice to pick something minimal that would be able to play back noise colors in order to mask the weapon noise.

The combination between a regular headphone set and a cheap music/MP3 player are perhaps the baseline tools to mask the weapon noise.

Perhaps one of the most representative earbuds are the Anker Earbuds A20 that are created following a kickstarter crowdfunding and are specifically designed with defeating anything from sleep apnea to helping any sort of sleep disorder by integrating various elements such as a medical-design that makes the buds minimal enough to fit seamlessly inside the ear, Automatic / Electronic noise cancelling (to be done in the next followup release of the ear buds) and with built-in sensors that detect when the wearer falls asleep, at which point the earbuds commute to playing back a noise preset that can be created by the user as a combination of various sounds like waterfalls, fountains, noise colors, etc.

The Android application features a noise mixer where the user can pick and mix various sounds that the earbuds will play back when the earbuds switch to "sleep mode". As can be observed, the things that we talked about are already there, with "violet noise" and "pink noise" being some of the choices, along with the more Zen-inclined choices like waterfalls, forests and so on that are meant to mask background noise.

The buds more than likely have an internal memory and the sounds presented in the Android application mixer are more than likely seamless short clips that are then repeatedly played back by the ear buds.

The reviews for this device are overwhelming, and for the purposes of this document, in terms of quantity with a tremendous amount of people commenting on them and documenting their usage with way too many reviews mentioning issues along the lines of "Tinnitus" to be purely an organic manifestation.

Anker Earbuds A20 are not the only ones with other companies following shortly by releasing their own variants of earbuds designed as sleeping aids and with that said, the criticism we have is to be interpreted purely in terms of class of technology with the problems revolving around earbuds being an issue of architecture constraints that make the earbuds a good but expensive solution to get right. Here are some of the problems and design challenges that would make effective sleep ear buds difficult to create or would bump up the price just due to constraints:

• the buds have to be designed to fit seamlessly inside the ear while keeping in mind that the user should be able to sleep on their side without the ear bud sticking out of their ear and pressing against the pillow, which makes these sleep earbuds very small with a range of consequences across the board that limit the capabilities of the earbuds just due to that,
  • battery lifetime is short due to the small size and no room to fit a larger capacity battery; battery lifespan is also short and prolonged usage will very speedily reduce the battery lifespan with the battery also being in most cases, not only the Anker Earbuds A20, unserviceable by the user and cannot be replaced,
  • the main difference between sleep earbuds and regular earbuds is really just the size such that depending on the situation, the ear size of the person, the pillows and others, it is possible to just use regular earbuds and just play back the masking noise, provided that the earbuds are not annoying to sleep on,
• ear wax can easily block the small speakers of the earbuds to the point that there is literally no noise coming out of the earbuds making them seem broken,
• the automatic switching specific to the Anker Earbuds A20, that switches from listening to "sleep mode" based on a sensor that detects when the user falls asleep is superfluous and not necessary, as well as being a little bit of an anti-design given that the user typically has problems falling asleep in the first place but after that the noise being mostly irrelevant; with that said, just a manual approach would have been enough and most users report switching off this feature that takes up design space unnecessarily while not providing anything too practical,
• the Android application specific to the Anker Earbuds A20 allows users to generate sound mixes based on presets but we were unable to determine whether the user can upload their own soundclips (apparently, it is not possible) and while there are a lot of presets available, right about any user that has the know-how to use these ear buds also has the know-how to google or find their own sounds on YouTube and then play them back with software like Mixere or any other sound application; Youtube alone has an impressive amount of seamless "1 hour" or even "10 hour" looped tracks available for various sounds, snippets of music clips and others that can just be downloaded, converted to a sound clip and then used with the ear buds making the Android application for the Anker Earbuds A20 cute but ultimately not really necessary,
• active noise cancelling (ANC) only marginally manages to block the weapon noise that we are documenting such that having earbuds with or without ANC is mostly the same; interestingly, we have found that the weapon noise is actually dispersed more easily when the ANC-mode is "transparency" that ironically is a mix between outside noise and the audio being listened to

All-in-all we've found that sleep earbuds in general, even regardless of the brand, are a beautiful display of technology but the constraints make such earbuds a whim just for the purpose of defeating this weapon noise, "Tinnitus" or sleep apnea with very cheap variants being available that make such an expensive device unnecessary. Don't get us wrong, the Anker Earbuds A20 are so pretty and comfortable that we would want to wear them ALL the time, not only for the purpose of sleeping or dispersing the weapon noise, but for this document they represent perhaps the best item on the market that regrettably is overpriced for the purpose.

Sleep headbands are the best solution that we have found to be the most effective in defeating this weapon while at the same time being compatible with sleeping such that a subject will be able to seamlessly transition between performing daily tasks and taking naps. Additionally, sleep headbands are way larger than sleep buds and hence have way more wiggle room in terms of technological design, allowing for larger speakers, better and larger batteries and able to integrate even more technologies such as ANC at a bargain price.

There are just so many brands and sub-brands of these devices that are all Chinese knockoffs off each other that are great at masking out the weapon noise while being available at prices as low as ten bucks. Ironically, as cheap as they are these headbands have a huge playtime that reaches up to half a day playtime due to the battery being located at the front with the observation that the user will never end up sleeping with their face flat down. Most of these headbands, just like the earbuds, have Bluetooth connectivity with very standard chips that are compatible with any device that can play back sound ranging from mobile phones to desktop computers.

Furthermore, these headbands are remarkably comfortable, maybe less-so aesthetically pleasing than headphones that they can even be a replacement for regular heaphones. Due to their design that hides two speakers inside the headband, with a controller and battery hidden at the front, the headband is also impermeable to some degree making them useful for regular usage, sleeping, working out or sports events as well as being a "better alternative" to listening to music inside a helmet given that ear buds might have the tendency to fall out due to vibration.

We were unable to ascertain the existence of "high end" music headbands in order to cross-check the feature-set with the feature-set of the "ten bucks headbands" in order to determine how the price would scale with the effectiveness at masking out weapon noise. In fact, the only headbands available on Amazon are still low-cost and no-brand headbands and the low-cost headbands work so well that it is difficult to speculate what could be done better aside from the standard "optimizations" like adding a larger battery.

To be fair, these are perhaps the best variant of headphones that can defeat the sonic weapon being discussed in this document and it can do so for about ten bucks; ten bucks for which the whole psychological suggestive mumbo-jumbo just falls apart. We are so impressed with these, compared to the alternatives and given the low cost, that we have no words and never thought that defeating the noise weapon would be so easy.

One of the efforts in Eastern Europe starting from a few years back to the time of writing is the "thermal isolation" of Soviet-style rebar residential buildings. The process involves applying a coating of Styrofoam plates all around the building block in order to increase the thermal isolation of the building. One of the interesting side-effects of the effort is that Styrofoam is also great at reflecting sound frequencies with the "impressionable points" of the human audible spectra falling very conveniently in the most absorbed frequency ranges of Styrofoam.

A paper by Magda E. Tawfik et al. in the Journal of Applied Polymer Science titled "Hard wood-composites made of rice straw and recycled polystyrene foam wastes" offers a plot of the most absorbed noise frequencies by the various types of Styrofoam.

The figure is labeled with "Sound absorption coefficients of recycled expanded polystyrene foam waste (PS), hard wood composite (HWC) and hard wood-composite with maleated polystyrene (HWCg)." and it can be observed that frequencies above seem to be absorbed very well by "polystyrene foam waste" (PS) as well as hard-wood composite (HWC) marked as the blue, respectively orange plots on the chart.

In fact, the Styrofoam acts like a band-pass filter for the most relevant part of the human audible range dampening both low and high frequencies that are not easily heard by the human ear, thereby providing some very nice isolating for very annoying sounds in both extremes of the audible frequency range. It is one bet that the Styrofoam will hence provide some dampening of the weapon itself, in case the source of the weapon is on the outside of the building, which somehow seems to be the case to some level given the difference in dampening relative to the outside.

Of course, this is not to say that the effort to increase the thermal isolation of buildings factored in the audio properties of the Styrofoam but it is worth mentioning because it is very incidental that Styrofoam provides great sonic isolation at a very cheap price.

Even though not directly related to the weapon analyses in this article, there is a technology related in terms of being a sonic weapon, that has amassed some interest over time with the usual discussions oscillating between "it's a myth and you're crazy" and some actual patents and other documentation being brought to light.

The technology is loosely named "voice to skull" or V2K for short and in simple terms it is a "telephatic technology" that allows an operator to seemingly "inject thoughts" in a subject's mind but without other people in the surrounding area being able to hear the voice of the operator.

This technology is actually available over the counter and is related with the hissing sonic weapon in terms of the properties of human hearing. One of the public circuits is made by Kazunori Miura from Japan and it was published in Elektor magazine back in March 2011. The following image shows the circuit realized and available to be purchased over the counter on Amazon.

And we took the liberty to save the pages from the Elektor March 2011 magazine for archival and documentation purposes that pertain only to the circuit itself short of having to upload the entire magazine such that the documentation that describes the circuit and functionality can be consulted locally.

The functioning principle is also simple, a high-frequency oscillation is used as carrier "noise" for the very purpose that the hissing sonic weapon also picks high-frequencies, namely that the higher-frequencies travel at higher speeds and also have the property of being more directionally focused than lower frequencies that tend to bleed into every surrounding object (ie: low-hum vibrations). The carrier "noise" is then used to modulate a simple voice recording such that the high-frequency noise will just be the carrier but the voice will still play back normally when delivered. The combined effect of a high-frequency carrier and a regular recording will manage to project the voice recording over long distances and with the additional property that the device can be oriented to a subject in a crowd and only that subject will hear the voice.

Looking at the circuit, the device is pretty easy to create, the bottom left part of the circuit being just a voltage regulator based on a typical 7812 chip that we have used many times at Wizardry and Steamworks for various projects and the upper part of the circuit seems to rely on two ICs and represent the implementation of the device. The only cost sink would be to obtain the small ultrasonic speaker array, so one would have to purchase small speakers in bulk. However, Amazon has one such device available that unfortunately only ships to the U.S. and goes for USD140.

What is interesting to us and the reason we mention this V2K device on this page rather than on its own page is that when we analyzed the original sonic weapon resembling Tinnitus, we actually speculated without knowing for sure about those "impressionable" points that are characteristic to human hearing, by stating that those frequencies, namely , (which is the best frequency to center any audio device on that is meant for human hearing) and are more than likely the transmission frequency that one would like to chose for a concealed sonic weapon because those frequencies are heard better by the human ear than the surrounding frequencies (lower than to some point and higher than to some point) such that they would stand out in terms of perception to a subject. We even stated that the frequency seems very attractive because it is fairly high compared to the baseline such that it also has the property of achieving a better penetration in terms of projecting the sound through various mediums.

What we noticed while browsing around to find this ultrasonic V2K device is that the specifications mention that the device is made to work on which matches our hypothesis that those frequencies would be the frequencies to use for (concealed) sonic weapons.

Before this turns into the terrorism section looping around from counter-terrorism or starts looking like the Anarchist's cookbook, one idea would have been to purchase this device and then mount it on a PTZ caddy that we designed for the Catchaser 2000 ROV (or just use an older PTZ camera for the extra benefit of seeing the direction precisely) and then start sending secret messages to people in a crowd.