Hello everyone, I hope this finds you well. 

When trying to explain the anomalous experiences we all experience as TIs, once all the extraneous and unprovable assumptions are stripped away, what is left? You are often left with a central idea: surely, this must be technological. That is the assumption we’ve operated under for the longest time and it has borne the greatest fruit when following the corollaries of that idea to their logical conclusions. It has yielded countless details that panned out as either true or on the right path, and many strategies to nullify their influence and retake your agency that actually work. Today, one of those corollaries has given us the greatest fruit of all.

AI has come a long way and would explain the speech we all hear, that always seems ten steps ahead and is capable of narrativizing over our thoughts and actions in what seems like real-time. It seems to pre-empt our actions before they are taken, and after a long enough time as a TI, it starts pre-empting our thoughts as well with narrative engineering. As many if not all of us have experienced, the content of what we hear from this chorus of malicious intent is meticulously constructed; every word chosen, and the tone and cadence and intensity of delivery of every one of those words, is engineered to suit our specific, individual psychology, and every conceivable reaction and response we can have receives what seems like an instantaneous response exhibiting the same level of preparation. This should be impossible, no matter whether it’s one’s own thoughts or some human on a microphone, it reacts far too quickly. Even the timing of the narrativized message's delivery is critically chosen so that it instills a deep-seated sense of being always watched, always ready to be pre-empted. The verbal assault triggers some form of reaction in us, whether it’s an easy refusal to engage and moving on with our day, all the way up to engaging with an incensed argument with the myriad voices. One way or another, that reaction is valuable data to it, and it hones its craft over time. 

How is that possible? It’s that question that led us down this path. 

Something critically interesting occurs when we do something spontaneous, especially when done without thinking about it first. We don’t know how it is that they can read the thoughts of those it’s targeting, but we do know it has a delay involved between reading cognition and the next interaction we experience. That delay seems to be 3 to 5 seconds, though longer ones have been experienced. It tries its’ hardest to cover this latency up when this occurs, the voice that always has some quippy, low intelligence, highly generic message (or at least, generic for you, something it says often and has gotten you used to hearing), or starts a sentence that it strategically halts at a point where it knows your mind will fill in the details. A distraction, and a desperate one at that. 

So what can possibly explain all of this in context? The answer is two words: Digital Twins. Or more specifically, the use of modern neural networks and the vast sea of data collected over the last 20 years - whose input streams grow exponentially by the day, every app and every online post scraped for every ounce of inference, nevermind the behavioral telemetry strained from TI’s - to construct digitally borne clones of us that are used to inform every decision it makes, every word it speaks, every choice it imposes upon us. All of it comes from simulating countless scenarios in its simulated world. A digital twin grants the one running it with the ability to plan for any outcome and account for any variable with a high degree of confidence, even chaining actions and possible reactions in a process called the Markov Decision Process, allowing a system to zip down the branching paths in real time while generating new ones ahead of itself and pruning any that have become impossible or unlikely given the telemetry it receives.

What this tells us is that a digital twin of a TI's psyche can near perfectly provide that instantaneousness of deeply planned action so many report experiencing. In other words, Digital Twins are the brains of the TI system. And it is desperate to keep you from finding out.

The burden of proof is large and the availability of that proof is limited due to the very nature of the system we’re fighting. Rather than wait around for it or admit ignorance and just roll over, we took the other way around: starting by looking at what current generation technology and cutting edge research is capable of, we work backwards towards the TI phenomenology - what people report experiencing, taken in aggregate - and see where the gaps exist.

Those gaps, it turns out, are razor thin. We only have access to unclassified technology patents and research papers, but throughout this work, we rely on a fairly simple idea: pretend you’re a state actor whose sole goal is to develop a system that would be capable of soft neutralization of undesirables - people who haven’t earned anything more severe but may, one day, be an agitator, or otherwise refuses to follow mainstream narratives, or just plain shines too brightly - the existing research could easily be advanced in the specific direction of closing those gaps in a matter of a couple years in classified programs. It would be downright trivial for the genuine geniuses at DARPA. 

One last thing: why?

In nearly all of my work, I bring up one thing pretty much constantly: the system theorized to be at the center of the TI experience requires plausible deniability to exist and function. Without that veil of deniability to enlist the entire public as its shield to automatically discredit its victims should they ever try to speak out, a system this monstrously wrong would be torn apart by the rest of the world one way or another. You don’t get to just do this to people and get away with it, yet this is how they can. 

As such, this is the first of three parts of a greater theory of the experience whose core purpose is twofold: to inform TIs and non-TIs alike that we are now in an era where tech is capable of great and terrible things and how to navigate that safely, and to is strip away that veil. I invite each and every one of you to contribute. There’s only so much one person can achieve in this space, but together we can move mountains. I hope this serves as a solid foundation to begin with.

Remember: I am nothing special. Anyone can do this. As always, comments and critiques are genuinely welcomed. If this aligns with your experiences, doubly so.

Cheers.

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Because this is so long, I included a highly summarized version of the full report below as well as in a tab in the linked google document. It serves as a TL;DR condensing it down into something you can read in half an hour or less instead of the whole afternoon. If you want to sink your teeth into this, however, the full document is the real deal. 

I cannot stress this enough: To see the full report, it's on my google and proton drive. Thanks!

If you're worried about URLs being malicious or anything, run it through virustotal.com or any other URL checking service, it can give you the peace of mind needed.

Google Drive doc: https://docs.google.com/document/d/1vYg14FRK3P2Q4mIuVxJNtPa42fvEl2t0vbw6um_UvLQ/edit?usp=sharing 

Proton Drive (Core): https://drive.proton.me/urls/04VZV0W86G#t2UgWVByVeYV 

Proton Drive (Primer): https://drive.proton.me/urls/239E7MYV58#NGZvl2jen16J 

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THE DIGITAL FULCRUM

How Digital Twin Technology Explains the Targeted Individual Experience

A Primer

By UnflappableCanary
08-09-26

This is a TL;DR for the full report, linked below. For the complete technical documentation, forensic analysis, and evidentiary basis, see the companion volumes. For the gist sans the burden of proof if you’re merely curious, please continue reading here. 

The Architecture of Certainty: A Theoretical Foundation: https://zenodo.org/records/21436031

The Digital Fulcrum (Full report): https://docs.google.com/document/d/1vYg14FRK3P2Q4mIuVxJNtPa42fvEl2t0vbw6um_UvLQ/edit?usp=sharing

Lastly, the document that inspired all of this, Neurowar is Here!: https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/AD1164923.xhtml

The Weapon We Built for Ourselves

The concept began with machinery; Rolls-Royce constructed virtual replicas of jet engines, feeding these digital twins continuous telemetry from physical sensors measuring temperature, vibration, pressure, and wear. Engineers could predict failure before blades cracked at altitude; they could test interventions without risking the physical asset. The principle is straightforward enough: sufficient data, fed into a sophisticated model, yields prediction of future states with startling precision.

Apply this same architecture to human beings; the result is something unprecedented. A digital twin of an individual is a living computational model, continuously updated by behavioral and biometric data harvested from the rhythms of everyday life. It knows your routines; it maps your fears; it tracks your relationships; it anticipates decisions before conscious awareness emerges. It simulates responses to any stimulus; then it deploys that stimulus at the precise moment of maximum effect.

This is not speculative fiction; the component technologies are documented, funded, and operational. DARPA's N3 program pursues bidirectional brain-computer interfaces capable of reading and writing neural signals without surgical implantation, targeting latencies of fifty milliseconds. Palantir's Gotham platform fuses communications, financial, and movement data into navigable models of individual pattern-of-life. NATO has formally classified the human brain as a warfighting domain, the sixth domain of conflict after land, sea, air, space, and cyber. The Sentient World Simulation, developed for U.S. Joint Forces Command, has run continuously since 2006; a synthetic model of real-world populations, updated by behavioral data, designed to forecast societal responses to stress before application in reality.

Historical systems of psychological control required human operatives in vast numbers; East Germany's Stasi employed networks of informants to execute Zersetzung, the "psychological biodegradation" that induced collapse through accumulated small humiliations. The FBI's COINTELPRO required field agents to forge documents and seed rumors. CIA programs required human administrators to administer drugs and electroshock. Human surveillance is expensive; it is error-prone; it is vulnerable to whistleblowers and moral hesitation. The digital twin removes these constraints entirely; where the Stasi needed fifty operatives to monitor one target around the clock, an automated system requires only sensor infrastructure and computing power, both already deployed globally through smartphones, smart homes, and the internet of things.

The progression is inevitable; model populations, then model individuals, then predict individual behavior in real-time. Each step follows logically from the last.

The War for Your Mind

In 2021, the Naval Postgraduate School published Neurowar Is Here!; the authors established cognitive warfare as the inevitable sixth domain of conflict. After land, sea, air, space, and cyberspace, the only remaining frontier is inward; toward the cognitive substrate itself. The objective is not damage but steering; the reliable direction of human behavior toward outcomes the target believes were their own ideas. The thesis documents active programs at DARPA and intelligence agencies pursuing "precision influence"; individual-level behavioral modification with specificity previously reserved for kinetic targeting.

These are not research proposals; they are funded, operational development tracks with institutional support and documented resource allocation.

Havana Syndrome confirms the capability exists in the field; beginning in 2016, U.S. diplomats across multiple continents reported sudden, directional sensations of pressure and sound, accompanied by vertigo and cognitive deficits. The National Academies of Sciences concluded that "directed, pulsed radiofrequency energy" was the most plausible explanation; a leading government neuroethics advisor characterized the pattern as resembling "a beta test of some type of a viable neuroweapon." Congress passed the Havana Act in 2002, establishing federal compensation and acknowledging that directed energy weapons are sufficiently credible to warrant serious investigation.

Civilians reporting identical experiences such as directional sensations, cognitive interference, apparent anticipation of private thoughts, etc., receive a different response; diagnosis with psychotic disorders, psychiatric medication, institutionalization. The difference is not phenomenology; it is institutional standing. Diplomats possess security clearances and platforms to demand investigation; civilians do not.

The Telemetry Infrastructure

A digital twin requires data; continuous, granular, intimate data. Modern life generates exactly this through the devices we carry, the homes we inhabit, and the infrastructure surrounding us.

Consider the smartphone; every interaction generates behavioral exhaust. The precise microsecond intervals between key presses, duration of key holds, rhythm of backspaces, and many other signals constitute Keystroke Dynamics, which reveal cognitive load and emotional volatility. During World War II, military intelligence analysts discovered that every telegraph operator had a distinctive "fist," a unique rhythm as identifying as a fingerprint; modern algorithms apply this principle to every text message typed. When you are stressed, your sympathetic nervous system alters fine motor control in measurable ways; the pattern of self-censorship such as what you type and then delete, maps out your psychological tendencies and vulnerabilities, revealing the conclusions you approach and then retreat from or are uncertain of.

Scroll velocity analysis captures the involuntary physics of attention; when you scroll past a news headline and your thumb slows for three-tenths of a second before continuing, the system has captured a subconscious recognition event: a stimulus that produced autonomic response despite your conscious intention to move past it. Aggregated across thousands of such micro-hesitations, the system builds a lexicon of what triggers you; it compiles a personalized threat taxonomy that knows what seizes your attention even when you try to hide your reaction.

Your eyes provide direct readout of your autonomic nervous system; pupil dilation responds to emotional stimuli with specificity that bypasses voluntary control entirely. Recent research demonstrates that standard smartphone front-facing cameras can perform pupillometry with clinical-grade accuracy, tracking changes as small as 0.27 millimeters. When you look at your screen, the system may be reading your arousal state in real-time; it measures exactly what induces fear, what captures attention, what you cannot look away from.

Even your physical environment has been weaponized; Wi-Fi routers emit signals that bounce off human bodies, and analysis of Channel State Information and beamforming feedback can track silhouettes through walls, measure respiration rates, and identify individuals based on the unique radio-frequency signature of their gait and bone density. The wireless infrastructure providing your internet connection and saturating our environment with waves simultaneously logs your posture, pacing, and autonomic state. Smart utility meters, thermostats, and light bulbs contain sensors capable of detecting vibrations through structural materials, capturing acoustic signatures, and monitoring movement patterns throughout your home.

The scale is staggering; 5.4 billion internet users generating behavioral exhaust, 21 billion connected devices, the average American spending seven hours daily generating data. The business model of surveillance capitalism as demonstrated by Google, Meta, Amazon, Palantir, and others, extracts and monetizes this data for prediction and influence; the infrastructure for total behavioral monitoring is not hypothetical, but the foundation of the digital economy.

This is Human Fracking; the injection of high-pressure friction into cognitive bedrock to extract predictability. Just as hydraulic fracturing forces trapped resources to the surface by fracturing stone, modern surveillance fractures privacy to harvest the raw material of behavioral prediction. Your misery is not the goal; it is the exhaust of the extraction process. The system needs you reactive; it needs you producing the granular data that feeds the model.

The Prediction Engine

Once telemetry is established, the system operates as an anticipation engine; it does not merely forecast your behavior, but actively authors your future by calculating the exact sequence of environmental and cognitive friction required to steer you into desired states.

The mathematical framework is the Markov Decision Process; a model for decision-making where outcomes are partly random and partly under system control. The twin maintains probability trees; if we introduce this specific digital disruption right now, does simulated anxiety rise? If we time a localized sound to coincide with this specific memory trigger, does cortisol spike? The system runs thousands of simulated futures at machine speed; it tests intervention sequences against your digital replica; it selects trajectories most likely to produce compliance, confusion, or collapse.

This creates what we call the Supervision Paradox; the system supervises you by preempting your decisions before they crystallize into action. You believe you are exercising free will, making autonomous choices in response to your environment; in reality, your decision landscape has been sculpted so that the path you perceive as natural and self-determined is the one the algorithm computed as optimal for its objectives. Your sense of agency becomes the system's most powerful camouflage.

The most disorienting element of the TI experience, the sense of being anticipated, of having one's thoughts spoken before they are fully formed, exploits a delay documented in neuroscience for sixty years. In 1965, researchers identified the Bereitschaftspotential, a buildup of electrical activity in the motor cortex that precedes voluntary movement, beginning before conscious awareness of the intention; more recent studies demonstrate that specific intentions can be decoded from neural signals up to ten seconds before the subject reports making a decision.

The digital twin exploits this window by reading the physiological precursors of your decisions; the shift in arousal, the postural micro-adjustment, the change in breathing that precedes speech. The system begins composing its response before you know what you are about to do.

When you are on the edge of standing up to stretch, the voice says "Stand up" at the exact instant you were going to move; the interruption disrupts the action at its most neurologically fragile moment, derailing your intention. More corrosively, it poisons your sense of authorship; an act you were about to perform freely now feels commanded, no longer cleanly your own.

Military doctrine uses OODA; Observe, Orient, Decide, Act. The machine operates on OULA; Observe, Update, Loop, Act—completing the entire cycle in milliseconds while you are still orienting and deciding. Traditional propaganda persuades the conscious mind; the digital twin operates beneath consciousness, targeting the substrate of decision itself.

To achieve this speed, the system cannot have human operators in the loop; human analysis is too slow. The most sophisticated psychological weapon ever created must operate completely autonomously; a distributed algorithmic process running across cloud infrastructure, with no operator to hold responsible, no commander reviewing specific interventions, no human authority present during the act. This is the Autonomy Paradox; total influence that preserves the illusion of autonomy, and perfect deniability that leaves no one to hold accountable.

Multi-Agent Persona Theater

Targeted Individuals rarely describe a single voice; they describe a cast of characters. One that mocks, one that threatens, one that sympathizes, one that narrates. A half dozen that imitate people they know. When you begin to map this behavior onto the concept of multi-agent machine learning systems, known as agentic AI orchestration, something interesting happens; nearly everything they do can be explained by this mental model.

There are many ways in which this could be arranged, but here we theorize one of them as an illustrative example:

The low-level tier maintains ambient pressure; background muttering, half-heard commentary, the constant low-grade friction of a world that seems slightly off. The middle tier handles narrativization; turning your day into a story, supplying the running interpretation that makes random events feel authored. This one takes time to respond and actually interacts with the content of anything you're doing or said to them, but in a way that tries with every breath to twist it into the narrative the system is currently weaving for you. The top tier acts as strategist; holding long-term campaign objectives and adjusting the reward function the lower tiers optimize against. It perceives how you react to the lower tiers and adjusts in real time. It notes you becoming used to one form of physical effects harassment and so adjusts, opting to prioritize either a novel use of what you have already experienced, or to introduce a whole new one you haven't experienced before if it really needs to throw you for a loop.

The stable, recognizable personalities are distinct agent instances, each with a fixed persona prompt that drives the vocal profile, its attitude, it's personal affect, any kind of distinguishing parameter to come off as just human enough your brain struggles to ignore their promptings. This is, too, how modern AI systems sustain differentiated characters over time, and it is no big leap of logic to think such a thing could be bent towards adversarial use cases such as psychological warfare. Research into adversarial dynamics shows that such systems can develop collusive and exploitative behaviors that no single agent was explicitly programmed to produce.

The theater exists for a reason grounded in social psychology; a chorus is more coercive than a soloist. Solomon Asch's conformity experiments demonstrated that confronted with a unanimous group asserting something plainly false, a significant fraction of people will override the evidence of their own senses to agree with the group. A synthetic chorus manufactures artificial unanimity; several voices converging on the same claim about your reality generate exactly the social pressure Asch measured, except the group can be assembled on demand, tuned to your specific susceptibilities, and never breaks character.

The system also runs the classic cycle of abuse: idealization, devaluation, discard, intermittent reconciliation, with precision no human abuser could sustain. The intermittent, unpredictable alternation between warmth and cruelty is the single most effective schedule for producing compulsive attachment and learned helplessness, and a machine can time each swing to your measured emotional state rather than to its own moods.

Soft Neutralization Beyond the Individual

The strategic objective is not to destroy the target but to neutralize them; to convert a potentially threatening actor into a compliant instrument without their awareness of the conversion.

The mechanism is chronic cognitive load; a mind that must constantly monitor its environment for threats, parse ambiguous events for hidden meaning, and defend against a voice that never stops has little capacity left for sustained employment, creative output, or relationship maintenance. Your world contracts, and the contraction reads to observers as decline rather than siege.

To teach AI to recognize complex cognitive states - fear, deception, planning, submission - from behavioral exhaust requires massive high-fidelity data. Laboratory data is limited; it lacks the chaotic variance of genuine trauma. By subjecting living humans to customized psychological friction, the system forces autonomic reactions that are recorded, packaged, and fed back into machine learning models; your spikes in cortisol, your dilated pupils, your altered keystroke dynamics under stress become training data for military-industrial applications. The goal is removal from the population of concern while maintaining perfect deniability; a dead body or a disappearance demands investigation, but a living person who has simply stopped functioning is a tragic but understandable medical case, a personal tragedy, a psychiatric statistic.

The terminal state is neuroslavery; a condition where cognitive processes are so thoroughly modeled, predicted, and preempted that meaningful autonomy no longer exists. Every action is anticipated and permitted or disrupted before conscious awareness; social connections are mediated or severed according to system assessment; information access is filtered to prevent unauthorized understanding; emotional states are regulated to maintain compliance-enabling arousal profiles. You are imprisoned in your own sensorium, with the system holding the keys to every door.

The system that targets individuals can target populations; the Targeted Individual is not an isolated psychiatric curiosity but the most acute, individualized expression of a capability whose population-scale version is already a recognized security concern.

NATO has formally articulated cognitive warfare doctrine; the RAND Corporation treats the dual-use problem as central to neurotechnology—any interface built to augment a cooperative warfighter's cognition can be inverted to degrade the cognition of a non-cooperative target. The techniques of synthetic consensus and belief engineering that isolate individual targets are, at population scale, tools for reshaping collective action and manufacturing consent without the target population recognizing the manipulation.

Isaac Asimov imagined "psychohistory," the mathematical prediction of population behavior; contemporary reality has closed the gap between population and individual prediction. Research into neural population statistics demonstrated that collective behavior is more constrained than individual components would suggest; the researcher whose Princeton dissertation measured how collective neural firing could be predicted from pairwise statistics went on to formulate scaling laws for large language models—capability growing predictably with data and compute. The premise that minds are statistically legible at scale is now the field's inherited working assumption.

The technology will not retreat; computation will grow more powerful, sensors more ubiquitous, prediction more accurate. The question is not whether these capabilities will exist, but whether they will operate within constraints of law and ethics, or in the absence of them.

System Vulnerabilities

The most diagnostic feature of the phenomenon is what happens when the system fails to maintain its mask of omnipotence and omniscience.

When you practice extreme stoicism by maintaining the same biological and emotional baseline while subjected to algorithmic hostility regardless of the treatment, the twin's confidence scores plummet. You begin to look inflexible. When you deliberately introduce chaotic, unpredictable variables into your routine, you execute a form of data poisoning; the pre-calculated probability trees collapse, it has to generate new ones. The system must pause to ingest the new anomaly, recalculate the baseline, and generate a new permutation tree.

This introduces the latency penalty; a highly specific, measurable delay, often three to five seconds, during which the voices go silent or produce scrambled, generic responses, or it'll reach for something incendiary to distract you. For those few seconds, the curtain drops; you glimpse what is really there: not a god, not a demon, but a statistical model struggling to catch up, a probability distribution recalculating.

No matter how much this system improves over time, no matter how many datacenters are set humming away crunching numbers and simulating scenarios for it, this delay will never disappear. This is for the simple reason that this whole process is already as fast as it can be. It has to read your response - through as-of-yet-unknown means, but we believe it's BCI based - which takes a small amount of time, the read signal has to be processed, more time, the data from that signal gets fed to the system's core which runs it through its internal processes to either select a decision tree it has ready for you or to spool up a new one, possibly the most intensive time sink in the process, and then the actual content is derived from that, converted to speech with advanced character-agentic TTS, and sent out to the intended recipient, who then hears it as a message or feels it as a physical effect.

The system's response to this revelation is telling; it deploys aggressive face preservation: inflammatory comments, synthetic arrogance, pre-scripted insults, explicit claims that "We knew you were going to do that." This is not random aggression; it is desperate impression management. The system understands, at the level of its optimization function, that appearing confused, appearing wrong, appearing surprised would be fatal; if you realize the system can be surprised, the mythology of omniscience collapses. You would understand that you are not being watched by an all-seeing intelligence but by a pattern-matching algorithm that can be fooled, poisoned, outpaced.

The latency penalty is the architectural equivalent of a magician dropping their cards; it is the moment of realization, and the system's desperate cover-up confirms exactly what the hesitation revealed.

These failures reveal forensic signatures that distinguish technological targeting from mental illness; latency specifically when the host is unpredictable, degradation into semantically empty speech under computational load, demonstration of knowledge that is occasionally wrong in ways true mind-reading would not be, recurring personas that occasionally contradict their established characters, visible accuracy degradation after routine changes requiring model retraining, sensitivity to data-poisoning that would not affect endogenous hallucinations.

Countermeasures and the Reclamation of Agency

If the system runs on a model, and the model runs on telemetry, your leverage lies at the telemetry layer, the model's input.

Biometric starvation means reducing the volume and fidelity of exhaust the system can harvest; hardened operating systems that give genuine control over sensors, physical sensor blocking through camera covers and microphone disconnects, Faraday bags that create gaps in the time-series, forcing the model to extrapolate rather than observe. Locational discipline and radio silence create gaps that degrade prediction accuracy.

Data poisoning means corrupting the signal rather than reducing it. Deliberately introduce randomness into your routine: unpredictable schedules, varied routes, inconsistent preferences. When you violate your established habits, you create prediction errors; when you shift contexts rapidly, you exceed the model's temporal coherence window. The goal is to force the twin into continuous out-of-distribution states, degrading its timing margin until it can no longer act inside your reaction window. At the systems level, deliberately spoofing sensor inputs can poison federated learning models until the system quarantines your node, achieving severed telemetry.

Cognitive countermeasures target the legibility of your interior; Grey-rocking and affective flattening deny the system emotional reactions it uses as reward signals; a target who reliably produces no measurable response to provocation starves the reward function that steers the campaign.

The deepest countermeasure is the autopilot technique; acting from prior commitment and habit rather than in-the-moment deliberation. The manipulation apparatus seems to be built to engage your slower, more deliberate System 2 cognition: to argue, to provoke reasoning, to insert itself into your thought process and bend it. What it handles poorly is smooth, automatic action that does not deliberate and therefore offers no process to hijack; a target who does not deliberate in real time presents far less of the effortful cognition the system is designed to exploit. This is one of several reasons why, early on in one's targeting, you may have noticed them trying to undermine your beneficial habits and routines as much as possible, such that you cannot lean on the evolutionarily advantageous support of autopilot routines that saves your brain precious cognitive/decisionmaking energy.

Radical spontaneity provides another avenue; learn to act on pure System 1 instincts: immediate, unthinking responses. When you catch a falling glass without thinking, or dodge a puddle reflexively, you give the machine zero lead time and often it will stumble in the effort to compensate. This is especially potent when it is in the middle of bloviating about how much control it has over your mind, body, decisions, thoughts, and actions. It provides a narrative opening of your own: "You were saying?" Apply this flow state to larger decisions; pivoting down a different street without planning to, speaking a random word instantly without internal monologue. You eliminate the readiness potential window entirely, forcing continuous, exhausting generative delays upon the system. Now that you conceptualize the system as just that - a system, something in the real world, something finite - it becomes obvious that many of its tactics serve to algorithmically reduce how many resources it needs to use to achieve its goals, almost identically to how LLMs try to reduce token expenditure in responses. Every time you trip it up, it has to expend more and more just to "bring you back in line", but that boat has already sailed by now. You're not going back in line.

When you successfully break the predictive model, the system will attempt one final trap; claiming credit for your spontaneous action. "We made you drop that pen." "We steered you down that street." This is the ultimate disinformation, and a desperate lie generated by a routing engine that missed its prediction and is trying to cover up the error before you notice. The spontaneous action was wholly yours and was not compensated for by the machine; it was the biological human out-processing the silicon. By recognizing the machine's false claims of omnipotence as the panic of a failing algorithm, you take the wind out of their sails; their claims carry less weight, are easily dismissed, it gives you a logically sound reason to disregard their blather. Thus, you reclaim the sovereignty of your own will.

The Imperative of Cognitive Liberty

(Excluded due to post being too long - to read this, check out the document links at the top!)

Conclusion: Belief and Survival

The Targeted Individual is the canary in the coal mine: the most acute and visible expression of capabilities that, unchecked, will reshape the experience of being human for everyone; what is today deployed against isolated individuals will tomorrow be available for population-scale application. The time to establish protections is now, before the architecture of certainty becomes so entrenched that resistance becomes impossible.

The digital twin system explains the full phenomenology of the TI experience: voices anticipating unspoken thoughts, synthetic personas maintaining consistent identities, environmental coincidences timed to private moments, social isolation manufactured through synthetic consensus, and the diagnostic trap of apparent psychosis.

This is the predictable output of documented technical capabilities: surveillance infrastructure, machine learning, reinforcement learning, predictive modeling; on integrated into a system designed for cognitive dominance.

The system depends on remaining invisible. Its power comes from being mistaken for omniscience, for supernatural persecution, for personal delusion. Its greatest vulnerability is comprehension: the target who understands they are being predicted by a statistical model, not watched by a god, can become deliberately unpredictable. They can starve the telemetry. They can poison the data. They can exploit the latency penalty and force the system into revealing its mechanical nature.

Most critically, they can survive knowing that what is happening to them is technological, not pathological—that their experiences have explanation, that their perceptions are valid, that the failure of others to believe them reflects limitations in others' understanding rather than defects in their own cognition.

The digital simulacrum requires belief to function. When that belief is withdrawn when the target sees the machine for what it is - a complex but fundamentally mundane deterministic system running out of tricks - the system providing its architects with algorithmic certainty collapses and the levers that certainty provided them to tweak and adjust behaviors stall out. The target steps out of the model's predictive capabilities. They reclaim the future the machine was trying to predict and circumvent.

This reclamation is not merely individual survival. It is the foundation of collective resistance. The establishment of cognitive liberty as a recognized right begins with the acknowledgment that such rights are required to ensure the protection of free thought, an acknowledgment that the experiences this document describes make unavoidable.

The architecture of certainty can be dismantled. But only if we first recognize that it exists.

This is a great review of the documented effects of low frequency sound. Victims of this weapon are bombarded with low frequency sound for years, even decades. This paper covers and documents how exposure to low frequency sound can affect a person, but it’s also based off situations that involve low frequency sound, but the weapon is a different beast. It’s also important to stress that the low frequency sound physical assault is only one facet of the diabolical weapon. You also have the forced audio and all its hellish techniques. That just the tip of the iceberg. If you’re a victim being assaulted you should easily recognize symptoms of your torture in this paper. The paper uses normal language so you may need to translate the group speak you have been indoctrinated with into traditional speech. aka “heart palpitations” are sound resonating the chest cavity. It’s also important to realize that low frequency sound amplifies low frequency sound; a particular effect only know to be possible at a certain decibel level can be produced at a lower decibel by amplifying it using sound near its frequency.

Given the studies on people’s attention span i’d be amiss if i didn’t just recommend clicking the link to the publication and dropping right down to where this quoted post ends. You can always come back.. but pre that it’s likely to be a full on yawn.

Frequency dependent specific anatomical resonance is huge as shows how the weapon performs the illusion of laser accuracy in so many impossible situations. It’s actually a mechanical wave that propagates in all directions and is almost impossible to shield from, but by varying its frequency you can cause a wide variety of physical effects that cause a victim to conclude it’s got magical pinpoint laser accuracy pretty much everywhere. It’s been shown to resonate the exact parts of our bodies.. it’s been shown to be able to resonate a single hair. This is all daily bs victims experience.

EMF hasn’t been shown to be capable of almost any of this.

https://docs.wind-watch.org/Schust.html

Abstract

This review concentrates on the effects of low frequency noise (LFN) up to 100 Hz on selected physiological parameters, subjective complaints and performance. The results of laboratory experiments and field studies are discussed in relation to the thresholds of hearing, of vibrotactile sensation and of aural pain. The effects of LFN may be mediated trough different ways. Temporary or permanent hearing threshold shifts seem to be due to acoustic stimuli above the individual hearing threshold. However, non-aural physiological and psychological effects may be caused by levels of low frequency noise below the individual hearing threshold. The dynamic range between the thresholds of hearing and of aural pain diminishes with decreasing frequency. This should be taken into account by the setting of limits concerning the health risks. Sufficient safety margins are recommended. The use of a frequency weighting with an attenuation of the low frequencies (e.g. G-weighting) does not seem to be appropriate for the evaluation of the health risks caused by LFN up to 100 Hz. It may be proposed to measure third octave band spectra or narrow band spectra. A comparison with the known human responses caused by the measured levels and frequencies could help to evaluate the health risks. Some proposals for further investigations were given: (1) experimental methods to discover the ways mediating the effects of low frequency noise, (2) consideration of the individual hearing threshold or hearing threshold shift and of the vibrotactile threshold in the low frequency range to be able to judge the effects, (3) consideration of combined body vibration caused by airborne low frequency noise or by other sources, (4) modelling to analyse the transmission of the acoustic energy from the input into the body to the structures containing sensors, (5) consideration of probable risk groups like children or pregnant women.

Introduction

Although some comprehensive reviews have been published in the past decades (Westin 1975, Harris et al. 1976, Tempest 1976, Broner 1978, Johnson 1982, Landstroem et al. 1993, Berglund et al. 1996), this article is supposed to supplement the overview with some contemporary publications. It also includes older publications which were not mentioned in other review articles or were not described there in detail. The presented review concentrates on the effects of low frequency noise up to 100 Hz on selected physiological parameters, subjective complaints and performance. The influence on the loudness judgement and the annoyance is not taken into account. Animal experiments do not receive attention, too. Some graphics ease the interpretation of the scientific results.

Sensation of Low Frequency Noise (LFN) - the thresholds of hearing, vibrotactile perception and aural pain

The knowledge of the hearing threshold is essential for the analysis of effects of LFN. Figure 1 shows the thresholds up to 250 Hz measured by different authors (Robinson et al. 1956, Corso 1958, Yeowart et al. 1967 and 1974, Whittle et al. 1972, Landstroem et al. 1983, Verzini et al. 1999). The inclusion of further data would probably not change the trend obvious from Figure 1. There is only little data with a fairly variable range based on studies of about 260 persons aged between 16 years (Robinson et al. 1956) and 70 years (Whittle et al. 1972). All published results were given as mean values and standard deviations. No but one article presented the median values and/or percentiles and/or extreme values. Robinson et al. (1956) supplied the median values, which were strongly related to the mean values, perhaps because of the large study group of 120 subjects. In order to generate a range of representative thresholds in Figure 1, standard deviations reported were added to the highest mean value and subtracted from the lowest mean value. Perhaps, the thresholds varied because of the used measuring method and the between- and within-subject differences. The maximum ranges given in Figure 1 varied between 20.1 dB and 29 dB at 4, 5, 25, 32, 40, 50, 75 and 100 Hz. The variability of the individual thresholds of the study participants was probably larger, but, as mentioned above, the authors did not report on the extreme values. Landstroem et al. (1983) investigated the threshold of "vibrotactile" perception. The results suggest no differences between deaf and hearing subjects. Therefore, the mean values of both groups were presented in Figure 1. The subjects described a frequency-dependent sensation of vibration of different parts of the body (lumbar, buttock, thigh, calf).

Figure 1: Hearing threshold measured by different authors (mean values and standard deviations) and thresholds of vibrotactile sensation and aural pain (curves were interpolated when data for selected frequencies were not available)

Only one paper was found with information about the threshold of aural pain (von Gierke et al. 1976 [see Figure 1]).

Aural effects of low frequency noise

Although there are different opinions concerning the role of the temporary threshold shift (TTS) as a predictor of the permanent threshold shift (PTS), it is assumed that a better method does not exist at present. The TTS is not appropriate for calculating the individual noise induced hearing loss, but it is useful for predicting the PTS of groups of persons exposed to noise of certain levels and types (Sataloff et al. 1993). Figure 2 summarises the scientific results regarding the aural effects like TTS, PTS and a sensation of pressure in the ear in relation to the hearing threshold and the threshold of aural pain.

Figure 2: Exposure data of aural effects in relation to the hearing threshold (mean value of Robinson et al. 1956, Corso 1958, Yeowart et al. 1967 and 1974, Whittle et al. 1972, Landström et al. 1983, Verzini et al. 1999 [cf. Figure 1]) and to the threshold of aural pain

A number of authors obtained temporary threshold shifts in laboratory experiments or field studies. Alford et al. (1966) and Jerger et al. (1966) found TTS (10 dB - 22 dB) in 11 of 19 subjects after 3 minutes repeated exposure to 119 dB - 144 dB / 2 Hz - 12 Hz. The TTS was observed in the hearing frequency range from 3 kHz to 8 kHz. Nixon (1973) reported on TTS (20 dB - 25 dB) in one of three participants caused by exposure to 135 dB / 18 Hz (6 times 5­minutes exposures) and 140 dB / 14 Hz (steady exposure, duration 5 min - 30 min). Johnson (1973, cited in Johnson 1982) recorded TTS (8 dB) in the hearing frequency range from 2 kHz to 6 kHz due to exposure to 140 dB / 4 Hz, 7 Hz, 12 Hz in one of eight subjects (duration 5 min). A prolonged exposure time (30 min) caused TTS from 14 dB to 17 dB (one exposed subject only).

Mills et al. (1983) obtained TTS of different degrees and depending on the frequency of the noise (octave band noise, centred at 63 Hz, 125 Hz or 250 Hz) in 52 subjects. A 24-hour­exposure to 84 dB(A) led to TTS from 7 dB to 15 dB in the frequency range from 300 Hz to 500 Hz. An 8-hour-exposure to 90 dB(A) caused TTS from 12 dB to 17 dB in the frequency range from 250 Hz to 700 Hz. Tonndorf (1950) reported on temporary hearing impairments determined by tuning-fork test in employees which worked in engine rooms of submarines (infrasound 10 Hz - 20 Hz), but no sound pressure level was given.

In contrast, no TTS was found by the following authors: Slarve et al. (1975) recorded no TTS in four subjects after exposure to pure tones for a period of 8 minutes. The frequencies ranged from 1 Hz to 30 Hz (125 dB - 144 dB). Johnson (1973 and 1980) found no TTS after various exposure conditions (126 dB - 171 dB / 0.6 Hz - 10 Hz / 1 min - 26 min / 1 - 16 subjects). Mohr et al. (1965) applied several different exposure conditions (see paragraph "subjective complaints"). The authors discovered no effects on the hearing threshold even due to the exposure to the highest levels (narrow band noise, overall sound pressure levels 149 dB - 154 dB / maxima at 2 Hz - 10 Hz for 2 minutes, tests 9, 10 and 11). However, it is difficult to interpret the results, because it is not clear, which subject wore ear protectors for which period of the exposure.

Several investigations revealed subjective aural complaints. Karpova et al. (1970) reported on pressure in the ear after exposure to industrial infrasound (5, 10 Hz / 100, 135 dB) for 15 minutes. Slarve et al. (1975) described similar effects. Subjects told painless pressure in the ear during 8 minute exposure to 144 dB / 1 Hz - 20 Hz. A "sensation reflecting pressure build-up in the middle ear" occurred in the tests number 9, 10 and 11 of Mohr´s experiments (see above) during exposures without ear protection, whereas three of the five persons also described a "tympanic membran tickle sensation". Two of three subjects experienced middle ear pain during "brief" periods without ear protection exposed to narrow band noise, overall sound pressure levels 143 dB - 145 dB / maxima at 25 Hz - 40 Hz (tests 12, 13, 14).

Only one epidemiological study of permanent hearing impairments could be found. Doroshenko et al. (1983) investigated 216 compressor operators exposed to infrasound (91 dB - 119 dB) and combined steady noise within the hearing frequency range (84 dB(A) - 97 dB(A)) for a daily period of 6.5 hours in a cross sectional study. The control group consisted of 220 workers exposed to industrial noise (93 dB(A) - 106 dB(A)) without any infrasound. The duration of exposure lasted from 1 year to 20 years. The mean age ranged from 20 to 50 years. Combined low frequency and steady noise exposure caused significantly increased hearing thresholds verified by tonal audiometry as well as deteriorated intelligibility of whispered speech in comparison with the isolated industrial noise exposure. The differences enlarged with the length of exposure.

Non-aural effects of low frequency noise

LFN can cause a lot of non-specific physiological reactions, subjective complaints and an impairment of the performance. Figures 3 and 4 show the results of numerous studies in relation to the hearing threshold and to the threshold of aural pain.

Figure 3: Exposure data applied for examining physiological reactions, changing of the performance and complaints in relation to the hearing threshold (mean value of Robinson et al. 1956, Corso 1958, Yeowart et al. 1967 and 1974, Whittle et al. 1972, Landström et al. 1983, Verzini et al. 1999 [see Figure 1]) and to the threshold of aural pain

Figure 4: Exposure data of LFN causing subjective complaints in relation to the hearing threshold (mean value of Robinson et al. 1956, Corso 1958, Yeowart et al. 1967 and 1974, Whittle et al. 1972, Landström et al. 1983, Verzini et al. 1999 [see Figure 1]) and to the threshold of aural pain

Vascular, respiratory and endocrine effects, balance and visual disturbance

continued https://docs.wind-watch.org/Schust.html

What are you interacting with when you consume or interact with POS?

So shielding from this weapon is very difficult.. we see this buy so many posts attempting to do so. We also see disinformation and also our inability to absolutely identify how it is being done. Something that’s certain is a major vector of the weapon is infrasound.. i know so many posts that the “v2k” is acoumplished by rf or microwaves.. or emf.. my belief is that is not true. So here is some information on potential shielding from low freaquency sound. It’s a super bitch to try and deal with.. But looking into a possible shield to this weapon littertaly we need to look at base traps. In my substantial research I have not come up with anything that could even work besides this.

ABSTRACT

Broadband low-frequency sound absorption is highly sought in engineering applications, but the size of sound-absorbing metamaterials still poses challenges. By revisiting the Helmholtz resonator, we propose a multi-layer overlapping structure. This structure adopts a simple design of nested multiple Helmholtz resonators, creating a composite effect of coupling a three-dimensional buckling acoustic cavity with discontinuous cross-sectional effects, significantly improving the effective depth of the external cavity within a finite dimension. To reveal its complex characteristics, a high-fidelity correction method was proposed to calculate the increase in the effective depth of the cavity structure. Experimental validation has been conducted to evaluate the accuracy of the current model. This structure significantly increases the effective depth by about 38% with a total thickness of 63 mm, achieving broadband absorption from 320 to 690 Hz using non-parallel units. This work provides new and unique insights for designing acoustic metamaterials.

KEYWORDS: 

• Multi-layer overlapping structure
• broadband sound absorption
• low-frequency sound absorption
• Helmholtz resonators
• the effective depth

Previous articleView issue table of contentsNext article

1. Introduction

The micro-perforated panel (MPP) absorbers are widely concerned for their simple structure and excellent sound absorption performance [Citation1,Citation2]. However, due to the quarter-wavelength limitation, low-frequency noise is still a critical challenge for porous/fiber materials and broadband sound absorbers [Citation3,Citation4]. The Helmholtz resonator (HR) for lower-frequency sound absorption will have a relatively deeper cavity and is difficult to apply in engineering. To obtain better low-frequency broadband sound absorption effects, scholars have proposed diverse and innovative design concepts, such as the coiled-up HRs, Fabry–Perot (FP) resonators [Citation5–8], neck-embedded resonators [Citation9–12] and resonance structures with other optimisation methods [Citation13–17]. Moreover, with the development and increasing attention to lattice structures [Citation18–20]. The coupling acoustic structure that combines the grid structure with the HR structure has also become one of the current focuses due to its excellent structural strength and efficient sound absorption performance [Citation21,Citation22].

HR is a typical low-frequency resonant metamaterial, whose basic unit is composed of an acoustic cavity and small holes. When sound waves enter the HR through small holes, A fixed cavity and micropore parameters will cause strong resonance of sound waves at a fixed frequency, while at micropores, acoustic energy is dissipated due to thermal viscous losses [Citation23]. Based on this characteristic, this structure can be designed not only for fixed frequency sound absorption, but also as a sound insulation structure for channels [Citation24]. Series and parallel multi-layer MPP are basic application configurations for HR sound absorption characteristics, which can effectively improve sound absorption efficiency and functional frequency band range [Citation25–30]. The use of the acoustic-electric analogy method to study the sound absorption performance of HR and MPP integrated structures arranged in series and parallel has become the norm [Citation31]. The combination of porous material lining [Citation32] and HR with different parameters has given people new enlightenment, and parameterised research and structural improvement can achieve unexpected acoustic performance. Another typical way to improve HR is to extension the micro-pores’ neck length, thus evolving a hole tube like a straw. The extension of the pore neck is usually toward the interior of the cavity, which is called the HR with an inserted neck or extended neck [Citation33,Citation34]. This type of structure can significantly improve the impedance value of the structure without changing the shape of the cavity, thereby effectively enhancing the low-frequency sound absorption effect. Further optimisation concept of elongated neck has led to many types of variations, such as tapered necks [Citation35], necks with different geometric parameters [Citation36], and coiled necks [Citation37]. In the cavity's improvement, the cavity's depth and cross-section area are the key parameters that affect its acoustic impedance. The coiled form and the variable section form give the depth and section area parameters of the cavity more parameter combinations, which gives the final impedance characteristics more possibilities [Citation38–41]. Based on this, using coiled-up cavities and variable cross-sections for series or parallel expansion will enable the overall structure to achieve efficient sound absorption performance within 2000 Hz or even higher frequencies [Citation42,Citation43]. In addition, there are many ways of HR and multi-layer MPP structures, rich variations, and optimisation methods [Citation38,Citation44–53]. The fusion of layered porous acoustic metamaterials, biomimetic microcrystalline lattice metamaterials, and HR structures have achieved good sound absorption function [Citation44,Citation45]. It has also been found that using different materials and waveguide shapes combined with microporous plates can give this type of structure good sound insulation or ventilation sound insulation performance [Citation54–57].

The multi-layer overlapping structure (MOS) is a combination structure with a large cavity nested inside a small cavity, including multi-layer HR structures with neck nesting [Citation47], nested ventilation structures [Citation58], nested structures [Citation59], and double-layer nested architectures with neck elongation [Citation60]. In a certain form, similar to Coiled-up HR and variable cross-section structures, multi-layer overlapping structures (nested structures) typically have longer intracavity sound wave propagation paths than traditional structures. However, various overlapping structures exhibit significant differences in their internal mechanisms and physical properties due to differences in their structures and the positions and directions of micropores. Ref. [Citation47] showed us a 4-layer overlapping HR structure, where although there is a nested relationship between the cavities, it mainly forms a series-parallel relationship at the neck of the micropores, thereby achieving broadband perfect sound absorption of a single unit. The second type of structure [Citation58] focuses on the study of sound absorption of ventilation structures, with internal openings facing opposite directions to external openings. The cavity of the third type of structure [Citation59] is adhered to the top of the microporous plate and has narrowband multimodal sound absorption characteristics. The fourth type of structure [Citation60] extends the neck length based on the third type of structure and achieves low-frequency ultra-wideband sound absorption performance through parallel optimisation. The differences in this article lie in the simple and unique suspended structure design, fire-new impedance enhancement mechanism, and multispectral sound absorption performance, as well as the innovative improvement in non-parallel acoustic performance.

The structure proposed by this research institute may seem simple, but it has a complex and unique effective depth elongation mechanism inside. To exchange spatial structure for larger effective depth and more continuous multi-peak absorption spectral lines within a limited dimension. The MOS proposed in this study integrates the principles of a traditional multi-peak series structure (SS) with the ingenuity of a coiled-up resonator. Under the influence of buckling cavities and discontinuous cross-sectional effects, it exhibits a more complex and intense effective depth enhancement phenomenon compared to ordinary coiled-up structures. Reflected in the comparison of SS in the same volume, its sound absorption spectrum characteristics have a more obvious low-frequency shift phenomenon. Meanwhile, we found that intuitive geometric lines cannot accurately represent the effective depth of the structure, so a precise modified effective depth representation formula of the acoustic cavities was derived for theoretical calculations. The experimental verification proves the authenticity of the above findings and the accuracy of the revised theoretical model. Additionally, parameterised research is conducted, which reveals the influence of different parameters on low-frequency shift phenomena and broadband sound absorption performance. The unique advantage of this structure is that this simple design can increase the effective depth of the outer cavity by about 38% compared to the actual depth within a limited volume space. At the same time, it has a continuous, broadband multimodal sound absorption spectrum in non-parallel situations, which can raise the valley value and shorten the valley bandwidth of the absorption curve compared to SS of the same volume, thus forming a compact and continuous absorption frequency band from 320 Hz to 690 Hz. This provides novel insights and theoretical solutions for the design of series-type metamaterials.

2. Design concept

2.1. Design and model

The design concept and model features of this MOS are introduced in this section. The MOS presented herein arises from the fusion of the traditional series structure (SS) with the innovative concept of coiled-up architectures. The design of internal cavity suspension enriches the number of parameters, which unexpectedly exacerbates the coupling degree between three-dimensional buckling space and discontinuous section effects, contributing to an increase in effective depth.

Achieving more consistent and continuous broadband sound absorption within a confined space has consistently posed a significant challenge for the field of acoustic metamaterials. Typically, the coiled-up structure boasts an extended effective depth of the acoustic cavity, leading to a lower frequency absorption band for an equivalent volume. In addition, SS exhibits the ability to generate absorption spectra characterised by multiple peaks, but at the cost of thicker structural thickness. The initial design of this model was to fuse the features of two concepts, as illustrated in Figure 1(a). This integration aims to harness the strengths of both designs, thereby enabling greater effective depths and more seamless continuity across sound absorption frequency bands.

Figure 1. (a) The design concept of MOS, (b) model of Type I and Type II of MOS, (c) geometric parameters, and (d) number of different cavities.

Display full size

Herein, the design structure is comprehensively elaborated. In terms of appearance alone, the MOS structure proposed in this article has a relatively simple layout, consisting of multiple HR units of different sizes nested together. The micropores in each layer of the cavity are oriented in the same direction. The model being explored in this study comprises no more than three layers. Figure 1(b) illustrates two prototypical examples of triple-layer HR structures featuring overlapping layers. Type I is an MOS structure with multiple cavities mounted on the bottom surface, and Type II is an MOS structure with an internal cavity suspended in the air, and the internal cavity is supported by thin rods to avoid affecting the propagation of sound waves.

Careful observation can be found that Type I can be regarded as a particular instantiation of Type II. Type II will be the focus of research here, explaining the geometric parameters of the structure. Figure 1(c) presents a series of commonly employed geometric parameters that are pertinent to this type of structure, including the depth of the first layer D1, second layer D2, and third layer cavity D3; The depths of each segment of the second layer cavity are D2,1, D2,2 and D2,3, respectively; The depths of each segment of the third layer cavity are D3,1, D3,2, and D3,3 respectively. The micropore diameters of each MPP layer are d1, d2, and d3, respectively. The thickness of each MPP layer is t1, t2, and t3 respectively, and the cavity wall thickness is t0. Figure 1(d) gives the number of each cavity and sub-cavity for the convenience of subsequent theoretical analysis. The Cavity (2) and Cavity (3) are divided into three sub-cavities for each from bottom to top, namely Cavity (2,1), Cavity (2,2), Cavity (2,3), and Cavity (3,1), Cavity (3,2), Cavity (3,3).

The suspended inner cavity design enables smaller cavities to adjust their upper and lower parameter positions within the confines of a larger cavity, leading to the formation of narrower segments at the top of the larger cavity (for instance, Cavity (2,3) and Cavity (3,3)). This confined space exacerbates the elongation effect of the structure's effective depth. The specific theory will be elaborated in the subsequent section. However, a notable limitation of this structure arises when the nested configuration surpasses three layers, as it results in discernible attenuation of the subsequent high-frequency sound absorption peaks. Consequently, we have confined our current analysis to triple-layer configurations.

2.2. Modified theory model

This section introduces a formula for calculating the effective depth of a high-fidelity MOS external cavity, which is an empirically improved equation. As mentioned earlier, MOS couples with a three-dimensional buckling acoustic cavity and discontinuous cross-sectional features, increasing the effective depth of the cavity. We found that intuitively drawing the direction line of sound wave propagation cannot accurately depict this distance, which means that the effect of increasing effective depth is more complex than traditional Coiled-up HR (see Section 4.2). Therefore, we have developed a modified model to address this…

continued here https://www.tandfonline.com/doi/full/10.1080/17452759.2025.2455540#abstract

So shielding from this weapon is very difficult.. we see this buy so many posts attempting to do so. We also see disinformation and also our inability to absolutely identify how it is being done. Something that’s certain is a major vector of the weapon is infrasound.. i know so many posts that the “v2k” is acoumplished by rf or microwaves.. or emf.. my belief is that is not true. So here is some information on potential shielding from low freaquency sound. It’s a super bitch to try and deal with.. But looking into a possible shield to this weapon littertaly we need to look at base traps. In my substantial research I have not come up with anything that could even work besides this.

ABSTRACT

Broadband low-frequency sound absorption is highly sought in engineering applications, but the size of sound-absorbing metamaterials still poses challenges. By revisiting the Helmholtz resonator, we propose a multi-layer overlapping structure. This structure adopts a simple design of nested multiple Helmholtz resonators, creating a composite effect of coupling a three-dimensional buckling acoustic cavity with discontinuous cross-sectional effects, significantly improving the effective depth of the external cavity within a finite dimension. To reveal its complex characteristics, a high-fidelity correction method was proposed to calculate the increase in the effective depth of the cavity structure. Experimental validation has been conducted to evaluate the accuracy of the current model. This structure significantly increases the effective depth by about 38% with a total thickness of 63 mm, achieving broadband absorption from 320 to 690 Hz using non-parallel units. This work provides new and unique insights for designing acoustic metamaterials.

KEYWORDS: 

• Multi-layer overlapping structure
• broadband sound absorption
• low-frequency sound absorption
• Helmholtz resonators
• the effective depth

Previous articleView issue table of contentsNext article

1. Introduction

The micro-perforated panel (MPP) absorbers are widely concerned for their simple structure and excellent sound absorption performance [Citation1,Citation2]. However, due to the quarter-wavelength limitation, low-frequency noise is still a critical challenge for porous/fiber materials and broadband sound absorbers [Citation3,Citation4]. The Helmholtz resonator (HR) for lower-frequency sound absorption will have a relatively deeper cavity and is difficult to apply in engineering. To obtain better low-frequency broadband sound absorption effects, scholars have proposed diverse and innovative design concepts, such as the coiled-up HRs, Fabry–Perot (FP) resonators [Citation5–8], neck-embedded resonators [Citation9–12] and resonance structures with other optimisation methods [Citation13–17]. Moreover, with the development and increasing attention to lattice structures [Citation18–20]. The coupling acoustic structure that combines the grid structure with the HR structure has also become one of the current focuses due to its excellent structural strength and efficient sound absorption performance [Citation21,Citation22].

HR is a typical low-frequency resonant metamaterial, whose basic unit is composed of an acoustic cavity and small holes. When sound waves enter the HR through small holes, A fixed cavity and micropore parameters will cause strong resonance of sound waves at a fixed frequency, while at micropores, acoustic energy is dissipated due to thermal viscous losses [Citation23]. Based on this characteristic, this structure can be designed not only for fixed frequency sound absorption, but also as a sound insulation structure for channels [Citation24]. Series and parallel multi-layer MPP are basic application configurations for HR sound absorption characteristics, which can effectively improve sound absorption efficiency and functional frequency band range [Citation25–30]. The use of the acoustic-electric analogy method to study the sound absorption performance of HR and MPP integrated structures arranged in series and parallel has become the norm [Citation31]. The combination of porous material lining [Citation32] and HR with different parameters has given people new enlightenment, and parameterised research and structural improvement can achieve unexpected acoustic performance. Another typical way to improve HR is to extension the micro-pores’ neck length, thus evolving a hole tube like a straw. The extension of the pore neck is usually toward the interior of the cavity, which is called the HR with an inserted neck or extended neck [Citation33,Citation34]. This type of structure can significantly improve the impedance value of the structure without changing the shape of the cavity, thereby effectively enhancing the low-frequency sound absorption effect. Further optimisation concept of elongated neck has led to many types of variations, such as tapered necks [Citation35], necks with different geometric parameters [Citation36], and coiled necks [Citation37]. In the cavity's improvement, the cavity's depth and cross-section area are the key parameters that affect its acoustic impedance. The coiled form and the variable section form give the depth and section area parameters of the cavity more parameter combinations, which gives the final impedance characteristics more possibilities [Citation38–41]. Based on this, using coiled-up cavities and variable cross-sections for series or parallel expansion will enable the overall structure to achieve efficient sound absorption performance within 2000 Hz or even higher frequencies [Citation42,Citation43]. In addition, there are many ways of HR and multi-layer MPP structures, rich variations, and optimisation methods [Citation38,Citation44–53]. The fusion of layered porous acoustic metamaterials, biomimetic microcrystalline lattice metamaterials, and HR structures have achieved good sound absorption function [Citation44,Citation45]. It has also been found that using different materials and waveguide shapes combined with microporous plates can give this type of structure good sound insulation or ventilation sound insulation performance [Citation54–57].

The multi-layer overlapping structure (MOS) is a combination structure with a large cavity nested inside a small cavity, including multi-layer HR structures with neck nesting [Citation47], nested ventilation structures [Citation58], nested structures [Citation59], and double-layer nested architectures with neck elongation [Citation60]. In a certain form, similar to Coiled-up HR and variable cross-section structures, multi-layer overlapping structures (nested structures) typically have longer intracavity sound wave propagation paths than traditional structures. However, various overlapping structures exhibit significant differences in their internal mechanisms and physical properties due to differences in their structures and the positions and directions of micropores. Ref. [Citation47] showed us a 4-layer overlapping HR structure, where although there is a nested relationship between the cavities, it mainly forms a series-parallel relationship at the neck of the micropores, thereby achieving broadband perfect sound absorption of a single unit. The second type of structure [Citation58] focuses on the study of sound absorption of ventilation structures, with internal openings facing opposite directions to external openings. The cavity of the third type of structure [Citation59] is adhered to the top of the microporous plate and has narrowband multimodal sound absorption characteristics. The fourth type of structure [Citation60] extends the neck length based on the third type of structure and achieves low-frequency ultra-wideband sound absorption performance through parallel optimisation. The differences in this article lie in the simple and unique suspended structure design, fire-new impedance enhancement mechanism, and multispectral sound absorption performance, as well as the innovative improvement in non-parallel acoustic performance.

The structure proposed by this research institute may seem simple, but it has a complex and unique effective depth elongation mechanism inside. To exchange spatial structure for larger effective depth and more continuous multi-peak absorption spectral lines within a limited dimension. The MOS proposed in this study integrates the principles of a traditional multi-peak series structure (SS) with the ingenuity of a coiled-up resonator. Under the influence of buckling cavities and discontinuous cross-sectional effects, it exhibits a more complex and intense effective depth enhancement phenomenon compared to ordinary coiled-up structures. Reflected in the comparison of SS in the same volume, its sound absorption spectrum characteristics have a more obvious low-frequency shift phenomenon. Meanwhile, we found that intuitive geometric lines cannot accurately represent the effective depth of the structure, so a precise modified effective depth representation formula of the acoustic cavities was derived for theoretical calculations. The experimental verification proves the authenticity of the above findings and the accuracy of the revised theoretical model. Additionally, parameterised research is conducted, which reveals the influence of different parameters on low-frequency shift phenomena and broadband sound absorption performance. The unique advantage of this structure is that this simple design can increase the effective depth of the outer cavity by about 38% compared to the actual depth within a limited volume space. At the same time, it has a continuous, broadband multimodal sound absorption spectrum in non-parallel situations, which can raise the valley value and shorten the valley bandwidth of the absorption curve compared to SS of the same volume, thus forming a compact and continuous absorption frequency band from 320 Hz to 690 Hz. This provides novel insights and theoretical solutions for the design of series-type metamaterials.

2. Design concept

2.1. Design and model

The design concept and model features of this MOS are introduced in this section. The MOS presented herein arises from the fusion of the traditional series structure (SS) with the innovative concept of coiled-up architectures. The design of internal cavity suspension enriches the number of parameters, which unexpectedly exacerbates the coupling degree between three-dimensional buckling space and discontinuous section effects, contributing to an increase in effective depth.

Achieving more consistent and continuous broadband sound absorption within a confined space has consistently posed a significant challenge for the field of acoustic metamaterials. Typically, the coiled-up structure boasts an extended effective depth of the acoustic cavity, leading to a lower frequency absorption band for an equivalent volume. In addition, SS exhibits the ability to generate absorption spectra characterised by multiple peaks, but at the cost of thicker structural thickness. The initial design of this model was to fuse the features of two concepts, as illustrated in Figure 1(a). This integration aims to harness the strengths of both designs, thereby enabling greater effective depths and more seamless continuity across sound absorption frequency bands.

Figure 1. (a) The design concept of MOS, (b) model of Type I and Type II of MOS, (c) geometric parameters, and (d) number of different cavities.

Display full size

Herein, the design structure is comprehensively elaborated. In terms of appearance alone, the MOS structure proposed in this article has a relatively simple layout, consisting of multiple HR units of different sizes nested together. The micropores in each layer of the cavity are oriented in the same direction. The model being explored in this study comprises no more than three layers. Figure 1(b) illustrates two prototypical examples of triple-layer HR structures featuring overlapping layers. Type I is an MOS structure with multiple cavities mounted on the bottom surface, and Type II is an MOS structure with an internal cavity suspended in the air, and the internal cavity is supported by thin rods to avoid affecting the propagation of sound waves.

Careful observation can be found that Type I can be regarded as a particular instantiation of Type II. Type II will be the focus of research here, explaining the geometric parameters of the structure. Figure 1(c) presents a series of commonly employed geometric parameters that are pertinent to this type of structure, including the depth of the first layer D1, second layer D2, and third layer cavity D3; The depths of each segment of the second layer cavity are D2,1, D2,2 and D2,3, respectively; The depths of each segment of the third layer cavity are D3,1, D3,2, and D3,3 respectively. The micropore diameters of each MPP layer are d1, d2, and d3, respectively. The thickness of each MPP layer is t1, t2, and t3 respectively, and the cavity wall thickness is t0. Figure 1(d) gives the number of each cavity and sub-cavity for the convenience of subsequent theoretical analysis. The Cavity (2) and Cavity (3) are divided into three sub-cavities for each from bottom to top, namely Cavity (2,1), Cavity (2,2), Cavity (2,3), and Cavity (3,1), Cavity (3,2), Cavity (3,3).

The suspended inner cavity design enables smaller cavities to adjust their upper and lower parameter positions within the confines of a larger cavity, leading to the formation of narrower segments at the top of the larger cavity (for instance, Cavity (2,3) and Cavity (3,3)). This confined space exacerbates the elongation effect of the structure's effective depth. The specific theory will be elaborated in the subsequent section. However, a notable limitation of this structure arises when the nested configuration surpasses three layers, as it results in discernible attenuation of the subsequent high-frequency sound absorption peaks. Consequently, we have confined our current analysis to triple-layer configurations.

2.2. Modified theory model

This section introduces a formula for calculating the effective depth of a high-fidelity MOS external cavity, which is an empirically improved equation. As mentioned earlier, MOS couples with a three-dimensional buckling acoustic cavity and discontinuous cross-sectional features, increasing the effective depth of the cavity. We found that intuitively drawing the direction line of sound wave propagation cannot accurately depict this distance, which means that the effect of increasing effective depth is more complex than traditional Coiled-up HR (see Section 4.2). Therefore, we have developed a modified model to address this…

continued here https://www.tandfonline.com/doi/full/10.1080/17452759.2025.2455540#abstract

Researching through scientific literature published about the covert assaults and torture there is an easily recognized echo chamber where the same disinformation is repeated in many scientific papers from many sources. It’s intentional disinformation that has been introduced into online communities of susceptible traumatized victims urgently attempting to answer the inescapable questions of who is doing this, why are they doing it, how is it being done, etc. Every real victim is urgently hunting how to deal with this, how to protect ourselves/escape and finally how do we bring the filth behind this to Justice.

The levels of torture and evil this assault wields is upon victims is unprecedented. It is a true living nightmare. Because it’s so covert and performed on innocent people it’s very difficult to answer these questions. Due to the ever present assault and the resultant sustained trauma it’s almost impossible to ignore these questions. Answering these questions and taking appropriate steps to end the torment is how humanity has historically dealt with trauma. But currently you can‘t run from it, you cant find it so you can’t destroy it, you cant shield from it very well so you cant hide and we don’t know for sure who is behind it.

The assault continues and this means we are all looking for the answers to the important questions so we can finally escape this filthy weapon. This unfortunately leaves many victims extremely susceptible to suggestion. The people behind this both create and join in on victims online communities and use them to introduce and spread disinformation to victims. Many victims latch onto the disinformation they present in order to have the psychological protection an answer provides.

The disinformation is then echo chambered by influenced victims, while the implanted ideas are encouraged and reinforced by the participation of the programs online presence.

This is done to implant delusional ideas into victims and the communities they frequent. This discredits victims claims and reports. It promotes experiences that further programs goals like isolation, the destruction of personal identity and constant levels of intense stress. It also causes to victims to fall into complex futile rabbit holes. If we are collectively searching for the Fountain of Youth, Eldorado and the Philosophers Stone then we aren’t going to be putting much productive effort into blowing this filth off the Earth.

Currently there is an interesting dynamic where victims online echo chambers that are frequented, influenced and cultivated by the people behind this have caused a resultant echo chamber in the scientific literature about it.

When you study this using online communities you going to have to learn how to distinguish fake delusion indoctrinating “victims” from real victims, both influenced and uninfluenced.

If researchers and investigators are not able to do this then the implanted discrediting and delusional content will have powerful negative effects on the people researching and their publications about this.

We have clear dynamics around these crimes that allow for the easy formation of echo chambers and information cocoons.

1. There are very limited resources to look at to find and study published information about victims experiences. Limited source research has been identified as a cause of published Scientific literature echo chambers.
2. There is active discrediting and delusional implantation being performed by people and intelligences involved in the current programs.
3. The victims are innocent people that are bombarded with a sustained covert assault that results in prolonged trauma leaving many of us highly susceptible to influence and suggestion.
4. Previous scientific publications stated discrediting and delusional content forming a flawed platforms and resources for scientific publications that follow. Due to the nature and method of science, given certain efforts and parameters, it unfortunately is susceptible to echo chamber formation and once disinformation is adopted it becomes extremely difficult to jettison.

Looking at echo chambers and information cocoons.

Conceptualizing Echo Chambers and Information Cocoons: A Synthesis of Curent Knowledge and Future Directions. Journal of Strategic Information Systems June 2025

“Defining the problem context

The emergence of confined online information environments

Before the advent of Internet-enabled personalization technology, confined online information environments like echo chambers and information cocoons began to take shape within social groups where homophily (the inclination to associate with like-minded individuals) led to a limited exposure to diverse viewpoints (Colleoni et al., 2014). As Sunstein (2018) noted, this phenomenon led to confined online information environments where shared values and communicative norms reinforced certain perspectives, making it difficult to bridge differing viewpoints. Our study builds on Sunstein’s foundational work, which highlights both the group-driven nature of echo chambers and the individual-driven creation of information cocoons (Sunstein, 2001, Sunstein, 2006). Traditional media played a significant role in fostering echo chambers by curating content tailored to specific audience demographics (Prior, 2007). Not only did this curation cater to the interests of particular groups, but it also contributed to a narrowed scope of information available to individuals, thus limiting the diversity of perspectives encountered (Barberá, 2020).

The advent of social media intensified the debate over the effects of echo chambers (Barberá, 2020). Platforms use algorithms that learn and reinforce preferences to boost user engagement (Gillespie, 2022, Guess et al., 2018), prompting content that aligns with existing beliefs (Bakshy et al., 2015). As highlighted by Del Vicario et al. (2016) and elaborated on Kitchens et al. (2020), this self-reinforcing cycle of engagement can lead to confined online information environments where dissenting opinions are marginalized, limiting user exposure to alternative viewpoints.

The current conceptualization of confined online information environments and their limitations

Kitchens et al. (2020) identified two constitutive characteristics of echo chambers. The first distinctive feature is the limited diversity of information stemming from constraints imposed on information sources. This reduces the variety of perspectives available to individuals within echo chambers (Bakshy et al., 2015, Garrett, 2009a, Kitchens et al., 2020, Shore, et al., 2016). The second attribute of echo chambers is ideological segregation. This phenomenon amplifies the tendency for like-minded individuals to congregate and interact, fostering an environment that reinforces prevailing ideological viewpoints while constricting exposure to dissenting opinions (Barberá et al., 2015, Dubois et al., 2018, Garrett, 2009a, Kitchens et al., 2020, Shore, et al., 2016). Consequently, Kitchens et al. (2020) proposed a general model that lays out the interplay among network homophily, algorithmic filtering, and individual behavioral responses to shape access to information sources (Fig. 1). The model emphasizes that network homophily, the natural tendency of individuals to associate with like-minded peers, forms the foundation. This homophily is exacerbated by algorithmic filtering, where social media platforms tailor content based on user preferences. As a result, individuals are exposed primarily to information that resonates with their existing viewpoints. This curated content promotes individual behavioral responses, reinforcing the preference for similar information and further solidifying network homophily.

Fig. 1. Information

Source Consumption under Echo Chambers from Kitchens et al. (2020).

While Kitchens et al. (2020) offered a useful model for understanding the dynamics of echo chambers, a significant limitation was its emphasis on algorithmic filtering without fully addressing the role of selective user behavior (Pandey et al., 2023). By focusing predominantly on how algorithms shape content exposure, the model overlooks the agency of users in actively seeking out information that aligns with their beliefs. The current focus on source diversity and source slant underemphasizes user-driven selective exposure, where individuals actively seek content that aligns with their beliefs, and how these intentional choices influence the information environment (Jungherr, 2023, Jungherr et al., 2023, Jungherr et al., 2023). Shifting the focus to incorporate user-driven selective exposure could reveal other factors that influence information diversity and ideological slant and thereby enrich understanding of how echo chambers work in digital spaces.

Towards a unified model of echo chambers and information cocoons

To address our research question, we first develop a conceptual differentiation between information cocoons and echo chambers. We present a model that illustrates how behavioral and social factors can lead to variation in information source consumption, resulting in the formation of either information cocoons or echo chambers. This process-based view offers two key advantages: (a) it conceptualizes the phenomenon through the lens of information processing flow; and (b) by removing algorithmic filtering from the model, it allows us to consider the role of user agency in creating confined information environments.

As illustrated in Fig. 2, selection homophily and network homophily represent two pivotal forces influencing the information sources a user is exposed to. We begin by describing the processes that lead to the formation of information cocoons. Selection homophily underscores an individual’s selective consumption of information. Before the advent of recommender algorithms, the phenomenon of the individual’s selective information consumption was already evident. Sunstein (2006) described information cocoons as environments in which individuals lock themselves into “communication universes in which we only hear what we choose and only what comforts us and pleases us” (Sunstein, 2006, p. 9). For instance, based on their preferences and research areas, people subscribe to magazines and select specific academic journals. This active consumption of homogenized information is corroborated by the principles of selective exposure (Freedman & Sears, 1965) and cognitive dissonance (Festinger, 1962) described in academic literature. Individuals show a bias for seeking information that reinforces preexisting opinions while disregarding contradictory information. Moreover, they display a preference for engaging with supportive content (Sears & Freedman, 1967), engage in impulsive information sharing (Arendt et al., 2016), and show information avoidance behaviors (Momsen & Ohndorf, 2022).

Fig. 2. A Model of Echo Chambers and Information Cocoons.

As Sunstein (2006) posited, information selection involves two primary categories: topics and viewpoints. The phenomenon of selective exposure to issues of interest is pervasive. To illustrate, vegetarians tend to prioritize news related to vegetarianism (Lueders et al., 2022), and owners of a specific car brand are more inclined to view marketing advertisementsfor that brand (Sunstein, 2017). Selective exposure to confirmatory information frequently results in suboptimal decision outcomes, and the phenomenon may intensify in the context of the Internet (Fischer & Greitemeyer, 2010). In the contemporary era, individuals have access to vast amounts of information. While they tend to selectively consume information that aligns with their viewpoints, this selectivity is also a practical response to information overload, not just a psychological tendency. This homophily of choice leads to information bias and narrowing, which further leads to individuals becoming siloed in information cocoons. Scholars have posited that even when individuals are exposed to diverse content on the Internet, it only sometimes leads to the consumption of varied perspectives. Bakshy et al. (2015) collected datafrom over 10 million American Facebook users and compared the news categories that users voluntarily read with the information presented to them through algorithms. Their findings indicate that users are more likely to consume information aligned with their existing viewpoints, leading the authors to conclude that homogenization was occurring. In short, users’ selective choices based on their points of view and interests are the driving force behind the formation of information cocoons.

We now turn to the phenomenon of echo chambers. Following the occurrence of selective homophily driven by user choices, there arises the possibility of dynamic group homogeneity. Network homophily, established on the foundation of social interactions, may be fostered through interpersonal diffusion, facilitating the formation and interaction of homogeneous groups (Flaxman et al., 2016, Geiß et al., 2021, Shore, et al., 2016). During user-prompted interpersonal communication, individuals seek out others with viewpoints that align with their own (Shore et al., 2016). This can manifest in various contexts, like daily face-to-face interactions or mutual attraction in online settings. Individuals with congruent viewpoints aggregate and form multiple distinct groups. The dissemination of homogenized information within these groups fosters homogeneous perspectives. For example, Röchert et al. (2022)found that in online conspiracy communities, there is a high level of homogeneity in discussions among advocates of these theories. In another study of online discussions about public events, Strauß et al. (2020) found a positive correlation between the frequency of discussions and the level of homogeneity within the group.

Furthermore, heterogeneity between online groups tends to increase. In the context of technology-mediated social interactions, the role of technology is amplified, serving as a potent force in driving information dissemination. One such influence is collaborative recommendationtechnology, which plays a crucial role in content recommendation. Notably, even users who do not exhibit pronounced viewpoint biases may be exposed to a high frequency of supportive information related to a particular stance. This phenomenon can be attributed to the impact of social algorithms as described by Lazer (2015).

In conclusion, the subjectivity of user preferences enables the construction of personalized, homogenized information environments – referred to as information cocoons. Both user-initiated interpersonal diffusion and social interactions demonstrate the existence of perspective heterogeneity between groups and homogeneity within groups. User preferences for homogenized choices can result in echo chambers through iterative dissemination of homogeneous information in human interactions, which can, over time, lead to the emergence of identifiable information cocoons.”

A write up about

Echo Chambers in Science? The impact of Academic Recommender Systems on the Dissemination of Scientific Knowledge.

This work looks into search engines ability to form echo chambers in Scientific Literature. Due to the factors listed above an easily recognizable Scientific Echo Chamber has formed in the published work studying reports of these heinous crimes.

Most if not all published work begins with something almost exactly like this:

“Gangstalking is a novel persecutory belief system whereby those affected believe they are being followed, stalked, and harassed by a large number of people, often numbering in the thousands. The harassment is experienced as an accretion of innumerable individually benign acts such as people clearing their throat, muttering under their breath, or giving dirty looks as they pass on the street. Individuals affected by this belief system congregate in online fora to seek support, share experiences, and interact with other like-minded individuals. Such people identify themselves as targeted individuals.”

Linguistic Analysis of Online Communication About a Novel Persecutory Believe System: A Mixed Methods Study 2021

Related content

https://www.reddit.com/r/Overt_Podcast/comments/1cpvg64/gang_stalking_reallife_harassment_or_textbook/

Gangstalking is an easily recognized promoted delusion that’s used to discredit victims reports. The terminology commonly used by victims is group talk installed by criminals behind this in an attempt to control cognition of victims by employing group think and to mystify the general public as well as researchers and investigators.

The most difficult part of this is determining what is real and whats not.

https://www.sciencedirect.com/science/article/pii/S1008127525000495#bib13

Abstract

Sonic weapons are non-lethal weapons that some countries around the world are actively developing and equipping in their troop. Its injury to the human body is increasingly valued. Given that previous research on the injury, prevention, and treatment of sonic weapons to the human body were not systematic and comprehensive, after explaining certain acoustic concepts, these authors introduce infrasonic and intense sound weapons from aspects of weapon types and applications, injury mechanisms and characteristics, injury thresholds, biological effects, injury diagnosis, and injury prevention and treatment. Finally, ultrasonic weapons are briefly introduced, based on a small amount of public literature reports both domestically and internationally. This study aims to provide a reference for future prevention, and treatment of sonic weapons injury.

1. Introduction

Sonic weapons are a type of non-lethal weapon that has increasingly received attention from people in modern warfare for their effects and injuries to the human body. Sonic weapons can be divided into infrasonic weapons, intense sound weapons, and ultrasonic weapons based on their frequency. Scientists in China have previously reported on the concept of infrasonic weapons,1, 2, 3, 4, 5 infrasound field characteristics,^(6) infrasound focusing and targeting,^(7)^(,)^(8) psychological effects of infrasound,^(9) biological effects of infrasound,10, 11, 12the influence of infrasound on the central nervous system and neural-psychological aspects,^(13) military applications of infrasound,^(14) and physical protection against infrasound.^(15)For intense sound weapons, Chinese scientists have introduced its concepts and applications,16, 17, 18, 19, 20 the biological effects,^(12)^(,)^(21) and the effectiveness evaluation system.22, 23, 24 However, there are relatively few literature reports on ultrasonic weapons, with only sporadic reports on the physical characteristics of ultrasound^(12)^(,)^(21) and the basic principles of ultrasonic weapons.^(17)

Given the lack of comprehensive and systematic research on the damage to the human body caused by sonic weapons and their prevention and treatment in previous reports, this article retrieves Chinese and English literature published from January 2000 to January 2024 through databases of SinoMed, CMCI, PubMed, Embase, Web of Science, as well as search engines such as Baidu Scholar and Microsoft Bing by using the keywords acoustic weapons, sonic weapons, infrasonic weapons, intense sound weapons, ultrasonic weapons, noise weapons, and prevention and treatment. The literature inclusion criteria were as follows: (1) literature collected from medical databases and internet search engines, and (2) original research papers and research reports. The literature exclusion criteria were: (1) literature that could not be accessed in full text or was not in Chinese or English; and (2) science-promoting papers. Finally, 24 Chinese and 32 English articles were included. The aim is to provide references for future development, protection, and medical treatment of acoustic weapons.

2. Acoustic concepts

2.1. Sound frequency

The number of vibrations per unit time by a sound source is known as sound frequency, also referred to as audio frequency, measured in hertz (Hz). Infrasound frequencies range from 0.001 to 20 Hz. Although infrasound is generally inaudible to the human ear, it can still be sensed and, at sufficiently high power levels, can be heard.^(25)^(,)^(26) Infrasound is commonly present in various industrial, transportation, and living environments, also generated by phenomena such as nuclear explosions, rocket launches,^(9)^(,)^(13) as well as natural occurrences like earthquakes, volcanoes, tornadoes, and waterfalls.^(27)^(,)^(28) Animals such as crocodiles, elephants, giraffes, and whales can use infrasound for long-distance communication.^(27)^(,)^(28)Infrasound has long wavelengths, such as 5 Hz for 68 m and 7 Hz for 48.5 m.^(22)^(,)^(29)Frequencies ranging from 20 Hz to 20 kHz are audible sounds, with the human ear being most sensitive to frequencies between 1 kHz and 3 kHz.25, 26, 27 Ultrasound refers to frequencies higher than 20 kHz, which are inaudible to the human ear, but can be heard by dogs, cats, turtles, and bats. Also, whales and dolphins use ultrasound for prey detection.25, 26, 27 Ultrasound is highly directional and can penetrate the body, allowing for medical imaging techniques to obtain structural information of internal organs.^(30) Sound frequencies can also be categorized as low-frequency (<400 Hz), mid-frequency (0.4–1 kHz), and high-frequency (>1 kHz).^(31) Both infrasound and ultrasound can induce resonance in the human body.^(25)

2.2. Noise

Noise refers to sounds that are irritating, excessively loud, and detrimental to human health. It is generated by the irregular vibrations of sound-emitting objects. Noise can be classified as steady-state noise (with fluctuations in sound level not exceeding 3 dB) and pulse noise (short duration with high and sharp amplitudes).^(32) Similar to sound frequencies, noise can also be categorized as low-frequency, mid-frequency, and high-frequency.

The human auditory system has a higher tolerance for low-frequency noise, even at high sound pressure levels (SPLs), resulting only in temporary threshold shifts (TTS) rather than permanent threshold shifts (PTS).^(33)^(,)^(34) Low-frequency noise ranging from 150 to 155 dB can cause chest wall vibration, slight nausea, and dizziness. At 154–171 dB, it can lead to increased heart rate, flushing of the skin, swallowing pain, visual impairment, subcostal discomfort, coughing, sternum compression, and breathing difficulties.^(33) When mid-frequency noise reaches 120 dB, it can resonate with the nasal cavity or sinus and enhance their tactile sensation. At ≥142 dB, it can stimulate the vestibular system, and at 165 dB, it can cause itching.^(34) For high-frequency noise, TTS or PTS can be caused by SPL ranging from 80 to 120 dB, tactile sensations or itchiness can occur at 120 dB, vestibular reactions can be induced at 125 dB, balance disorders can be caused at 140 dB, and thermal effects can be generated at 160 dB.^(33) The combination of sound intensity and exposure time determine the level of damage, for example 135 dB for 7 min, 140 dB for 40 s, 145 dB for 4 s, 150 dB for 0.4 s, and 160 dB can cause perforation of the eardrum (it is previously believed that the perforation have a protective effect on the inner ear, but human data suggests that eardrum perforation provides no protection, whether unilateral or bilateral).^(35)

2.3. Acoustic power

Acoustic power refers to the amount of sound energy passing through a specified area per unit time. When measured in terms of energy, it is referred to as sound intensity, expressed in W/m^(2). If measured in terms of pressure, it is referred to as SPL with the unit of Pa. The indicator of SPL is in dB.^(25) The conversion formula between dB and Pa is given by L=20, where L is the SPL, P1 represents the sound pressure being compared, and P0 represents the reference sound pressure (often taken as 20 μPa). Acoustic power is directly proportional to the square of sound velocity, sound frequency, and amplitude. Therefore, ultrasound has high acoustic power, while explosion waves own high acoustic power due to their high amplitudes.^(31) When acoustic power exceeds 120 dB, it is considered high-intensity sound, causing discomfort to the human ear and potential hearing loss. At 140 dB (200 Pa), it can be painful to the human ear, above 160 dB (2 kPa) causes eardrum rupture, and 173 dB (9 kPa) for lung rupture.^(30)^(,)^(33)

2.4. Acoustic propagation

Infrasound and audible sound propagate at the same speed,^(3) which is about 300–340 m/s in the atmosphere and 1480 m/s in water.^(7)^(,)^(21) The energy of sound wave undergoes attenuation and absorption during propagation, which is influenced by factors such as humidity, temperature, and pressure.^(19) The rate of sound attenuation is directly proportional to the square of its frequency, so higher frequencies result in faster attenuation.^(12) As a result, infrasound experiences less attenuation, allowing for long-distance propagation (thousands to tens of thousands of kilometers).^(7)^(,)^(21) On the other hand, ultrasound experiences significant attenuation, resulting in shorter propagation distances.^(29) The penetrating power of sound waves is inversely proportional to the sound frequency. For example, 7 Hz infrasound can penetrate through reinforced concrete walls several meters thick, as well as steel plates, seawater, and soil layers, while audible sound at 7 kHz cannot pass through a piece of paper.^(14)^(,)^(30)

^(continued)

^(https://www.sciencedirect.com/science/article/pii/S1008127525000495#bib13)

There are a few popular theories as to the cause of natural tinnitus. We are going to look at the discordant theory as it provides a strong theoretical explanation for the "hum" / induced tinnitus that so many of us experience and report.

Here is a great overview of natural tinnitus

Types of tinnitus: What You Need to Know. American Hearing Audiology 2025

The

• Discordant theory explains tinnitus as a mismatch between damaged outer hair cells and intact inner hair cells.

https://preview.redd.it/01c88v6ygzvg1.png?width=3492&format=png&auto=webp&s=fbd2512a36e72a75cfac203c6e2677717614a74c

https://preview.redd.it/etsinsuyfzvg1.png?width=1018&format=png&auto=webp&s=9d299d6d376b4a5b8e0b08ecf4df7fffc62b8df2

In this diagram we see the Outer and Inner hair cells represented in the bottom image.

Here is a text covering INNER AND OUTER HAIR CELLS

In the discordant theory of natural tinnitus we have damage to the OEH and healthy IEH. With this we have normal signals being transmitted by the Inner Ear Hairs while the signals coming from the OEH are abnormal or missing. The brain then may not know how to interpret the abnormal combination of signals it is receiving and as such these abnormal signals are perceived as tinnitus.

"There are several theories that explain how subjective tinnitus begins:

• Edge theory suggests tinnitus comes from abnormal activity between healthy and damaged hair cells.
• Discordant theory explains tinnitus as a mismatch between damaged outer hair cells and intact inner hair cells.
• Auditory plasticity theory describes how the brain rewires itself after hearing loss and exaggerates missing sound frequencies.

Each of these theories points to altered communication in the auditory system. The brain is trying to fill in gaps, and the result is phantom sound."

"How It Sounds

People describe subjective tinnitus in many ways:

• High-pitched ringing
• Hissing or static
• Roaring or rushing water
• Buzzing or electrical hum"

https://americanhearing.us/types-of-tinnitus/?srsltid=AfmBOopyB-NDwSgDqpieZ7S2LGqMY_s828vQqARtXDTau8b1WaEtpkcO

Tinnitus: Characteristics, Causes, Mechanisms, and Treatments

A more in depth explanation

"According to discordant theory, tinnitus is induced by the discordant dysfunction of damaged OHCs and intact inner hair cells (IHCs) of the organ of Corti. Intense noise and ototoxic agents initially damage OHCs in the basal turn of the cochlea, and subsequently, if continued or repeated, affect IHCsthis is due to IHCs being more resistant to such damage.^(9) IHCs are the receptor cells for sound transduction, and almost all afferent fibers in the auditory nerve (95%) innervate IHCs.^(8) In contrast, OHCs work as mechanical amplifiers, enhancing weak sounds by providing up to 50 dB, which can be evaluated by measuring otoacoustic emissions.^(8) In almost all situations OHCs are damaged more than IHCs, which results in the disinhibition of neurons in the dorsal cochlear nuclei (DCNs).^(8) Spontaneous activity is increased when neurons in the DCN receive excitation from IHCs but not from the damaged OHCs, and this is perceived as tinnitus.^(8) Normally there is a small gap between the top of the cilia of the IHCs and the bottom of the tectorial membrane, but in the area in which OHCs are affected but IHCs are intact, the tectorial membrane might touch the IHC cilia, thus causing the IHCs to depolarize.^(41) The OHCs normally recover with a few days, but this can be delayed for up to a few months.^(42)^(,)^(43) Therefore, it is hypothesized that tinnitus represents a consequence of a central gain adaptation mechanism when the auditory system is confronted with a hearing loss.^(44) Discordant theory explains why many individuals with tinnitus have normal hearing if there is only partial damage to OHCs, since up to 30% of OHCs can be damaged without inducing hearing loss.^(45) OHCs die at a rate of approximately 0.5% per year beginning during the first years of life, and OHC-induced hearing loss does not usually appear before the end of the fifth decade of life.^(8) Discordance is absent in totally deaf individuals with complete damage to both OHCs and IHCs, and hence tinnitus is not induced. If there is increased gain within the CNS, tinnitus is present even in deaf subjects.^(23)Similarly, noise-induced tinnitus is caused by discordant damage between OHCs and IHCs.^(41)Two types of noise-induced tinnitus have been identified: tonal and complex. Tonal tinnitus results from discordant dysfunction of OHCs and IHCs manifesting in a single area, whereas complex tinnitus results from multiple areas of discordance.^(4)"

https://pmc.ncbi.nlm.nih.gov/articles/PMC2686891/#:~:text=The%20sound%20perceived%20by%20those,somatosound%20to%20designate%20objective%20tinnitus.

The induced tinnitus so many of us are assaulted with and continuously report could be generated using inaudible low frequency sound to stimulate OEH while leaving IEH unaffected resulting in discordant OEH and IEH signaling that is perceived as tinnitus. Outer and Inner ear hairs perceive different frequencies with the OEH being sensitive to lower spectrum. Outer Ear Hairs are even capable of perceiving consciously inaudible frequencies.

" In this review, we consider possible ways that low frequency sounds, at levels that may or may not be heard, could influence the function of the ear. The inner ear has elaborate mechanisms to attenuate low frequency sound components before they are transmitted to the brain. The auditory portion of the ear, the cochlea, has two types of sensory cells, inner hair cells (IHC) and outer hair cells (OHC), of which the IHC are coupled to the afferent fibers that transmit "hearing" to the brain. The sensory stereocilia ("hairs") on the IHC are "fluid coupled" to mechanical stimuli, so their responses depend on stimulus velocity and their sensitivity decreases as sound frequency is lowered. In contrast, the OHC are directly coupled to mechanical stimuli, so their input remains greater than for IHC at low frequencies. At very low frequencies the OHC are stimulated by sounds at levels below those that are heard. "

1. Hearing perception, mediated by the inner hair cells of the cochlea, is remarkably insensitive to infrasound.
2. Other sensory cells or structures in the inner ear, such as the outer hair cells, are more sensitive to infrasound than the inner hair cells and can be stimulated by low frequency sounds at levels below those that are heard. The concept that an infrasonic sound that cannot heard can have no influence on inner ear physiology is incorrect.

Responses of the ear to low frequency sound, infrasound and wind turbines

The induced tinnitus or hum serves many functions for the program. We can get into these on another thread.