Sound is a pressure, and a tip on getting the most out of acoustic board (part 2)



A “paranormal state” in Soho

Mobbing isn’t some alien probe story, and the technologies used to “clear” properties and force them to sale aren’t rocket science. Much of it is old-school detective craft, the tricks and gimmicks of shady private investigators put to use in the name of real estate speculation.

Beam-focused speakers like the parametric or “directional,” SoundLazer and Audio Spotlight are gaining popularity on the consumer market. In advertising, they are gimmicks that interest consumers in listening to an ad. In crowded public venues, they deliver pinpoint messaging without disruption to others; for example, playing the description of a work of art to the single gallery patron who stands before it. For an interesting application of Holosonic’s directional speaker technology, see the 2007 writeup of the A&E (Arts & Entertainment) network’s Soho promotion of the ghostly premium series, Paranormal State (“Hear Voices? It May Be an Ad,” Advertising Age, Gawker (now defunct) remarked, “Schizophrenia is the new ad gimmick,” glumly adding, “How soon will it be until in addition to the do-not-call list, we’ll have a ‘do not beam commercial messages into my head’ list?” (

In the case of the real estate mobbing that has victimized me for more than three years, the use of beam-focused sound, whether parametric or parabolic, gives the mobbers a reasonable chance to “contain” or to limit the range of the mobbing sound so as to minimize the chance of witnesses. Sound spillage also turns out to be an issue with beam-focused sound, one I haven’t adequately touched on, but one that might be reason enough to ensure that the houses flanking the victim house are “friendlies.” In this residential neighborhood where the deep waters of Lake Washington reflect light and sound up the surrounding slopes built out with homes of increasing size and expense, controlling sound is a challenge. However, the reflection of sound may offer an ambient noise level sufficient to disguise the mobbing sound, or at least to confuse the ear as to its source. And with the mobbers’ “surround-sound” system of mobbing harassment, the distribution of sound sources into locations north, south, and aerial to the victim  house, is certain to create a fragmented acoustic experience for any passerby who thinks he heard something and to, in the end, confuse the ear.

Mobbers can also “aim” the sound beam to produce specific effects. For example, you can supposedly aim a parametric speaker close to the ear of the mobbing victim to give him the experience of a voice coming from “inside” his head (“he’s got voices in his head”); this is essentially what the A&E billboard did with directional speakers mounted to affect those who walked by. You can “bounce” (reflect) sound off of a wall near a mobbing victim to give it a faint and ethereal quality; you can aim the sound at a speaker or maybe even a water pipe, adding a new layer of sound to an existing acoustic transport. A patented overhead application of directional sound utilizes a “hemisphere” to deliver “the world’s most precise audio isolation,” something that might be required to make a mobbing house habitable to mobbers so long as the sound field spilled over the property line to the victim house (“Sound Dome Directional Audio,” Add-on functionality makes the sound dome motion-activated by the person who steps into its field. An optional LED light turns it into an overhead light fixture, thereby hiding it in plain sight (,

Some ultrasonic applications are at once more obscure and unsettling, like the speech-jamming gun theorized by some Japanese scientists as a means to ensure equal time for all those in conversation, by making speech physically impossible for that guy whose mouth is always open (, or the ultrasonic “pain field gun” or “sonic shockwave generator” ( whose purpose is physical deterrence, apparently by blunt-force trauma. I mention these last because I was recently contacted by a Seattle resident living in another part of town that has become a mecca for speculators. She described a concussive physical effect associated with the noise she believes is intended to harass her. I’m in no position to substantiate the claims of others who suspect that they may be the target of mobbing, but I was reminded of her description as I came across references to this sonic weaponry. Those who take up harassment, whether as vocation or hobby, likely keep an arsenal of sneaky ways to confuse and torment others, including sonic “guns.”

A fair portion of mobbing is also trade knowledge, that is, knowledge of the building trades. No one knows the materials, the joinery and channels that forge a homestead, better than a man of the trades. (Note that I don’t say “man” to slight women; after all, there are female serial killers, though few. Despite a preference for non-gendered pronouns, I say “man” because the wet dream of mobbing is male, at least when it comes to real estate.)

Tradesmen know about the conduction of sound because they put together structures to contain sound or to keep sound out. Mobbing victims learn about it in their victimization. Once you know beyond a doubt that as soon as you sit in front of the windows to work, the mobbers working from adjacent houses whose facades jut out further than yours will aim their parametric speaker at your windows, the windows that once framed a peaceful landscape becomes a vulnerability. Indeed, the very meaning of “window” is altered.

Sound is transmitted as a vibration. Window panes provide an exposed and easily available surface for the resounding of a waveform.When a parabolic speaker “projects” a beam of sound onto a window pane, its vibration affects the glass. The pane becomes a platen for acoustic leakage, the leakage of sound. Older windows with deteriorating glazing or windows whose panes are otherwise poorly sealed into the frame are especially vulnerable to acoustic leakage around the edges of the glass. Double-pane windows are constructed with an “air-gap” between the panes; this allows for the dissipation of the vibration of sound on the exterior pane, with the attendant deadening of sound, before it can move through the interior pane. Common points of acoustic leakage in homes may include windows, doors, vents—anything that by its substance, seam, joinery or form provides a channel for a current traveling from the outside in, or from the inside out; any private byway or conduit made to carry heat, air, water or light. These forms and faults provide a medium for the transmission of sound.

Automobiles that must soundly transport human beings over screeching highways in four-wheeled vibrating carriages, are constructed with great attention to acoustic leakage. The acoustic camera I suggested might be used to detect mobbing in Fighting crime with acoustic detection systems, a camera that visualizes sound, has a dual role in the automotive trade where it is used to locate the source of pesky noises under the hood as well as to test the quiet of the passenger compartment against the onslaught of the road. If a channel provides a transmission medium, the channel brings you sound. If a seal is broken by light, it is also breached by sound. When sound travels in air, it equalizes like air.

Sound travels as a wave and is influenced by pressure. Sound pressure is the measure of the effect of a sound wave on ambient atmospheric pressure. It is sound pressure, the delta between the ambient air pressure and the pressure of a sound wave, that causes the diaphragm of a condenser microphone to vibrate and its vibration to be converted to an electrical signal (“Microphone,” in Wikipedia, In contrast, a laser microphone detects the difference in the angle of reflectance of its own light when it focuses on on a window pane affected by the acoustic pressure of a private conversation on the other side.

Sound requires a transmission medium, a material substance that can propagate energy waves (“Transmission medium,” in Wikipedia, Air—warm or cool—is the most common transmission medium for the sound that we hear, but sound is also transmitted through liquid or solid. Building structures provide channels for the flow of transmission mediums for sound. Heating vents and ducting carry sound in air from room to room, from inside out and outside in, depending on the direction of movement in the air. Pressurized water pipes carry sound as well as water; plumbers listen for leaks in pressurized lines using contact microphones that are sensitive to vibrations in the specific transmission medium. When used for seismic purposes, contact microphones listen for sound in an earthen transmission medium; when used against a water pipe, the transmission medium is water. Building materials have an acoustic rating depending on its absorption of sound; new speakers on the market can turn walls and other surfaces into speakers by vibrating against them. Contact microphones make the speech of those who’ve lost their voice boxes audible. By tactile sensing, such microphones also make the sound of a snail’s heartbeat audible to the human ear. Hearing aids that use bone conduction transfer the pressure of sound directly to the bones of the skull for those who cannot hear the sound of the waves in the air. But no matter the sound, a sound wave requires a transmission medium, a medium in which to sound and find its amplitude. Sound literally cannot exist in a vacuum.

Sound pressure varies depending on the source of the sound. Auditory pressure, that is, sound wave pressure that is audible to the human ear, has a pressure level of 0 decibels (dB). In a “calm” room, the pressure may be 20-30 dB; normal conversation is heard at a pressure of 40-60 dB. The rustling of leaves has a pressure of 10, the same pressure as the breath of your lover resting in your arms. A long-range acoustic device fires at a pressure of 153; a stun grenade falls into the range of 158 to 172 dB. A shockwave flattens at 191. Holosonic’s Audio Spotlight has a sound pressure level of about 130 dB. This is also the threshold of human pain (“Sound Pressure,” in Wikipedia,, a fact which raises the question of safety of mobbing sound. In “The New Sound of Crowd Control, a 2014 Motherboard article, writer Alex Pasternack raises “serious concerns about what ‘sound cannons’ can do to the physical body, and in turn to the body politic.” (“The New Sound of Crowd Control,” in Motherboard, The article concludes that the long-range acoustic device, based on parabolic sound technologies, was never intended to be used as a weapon.

When you think about the nature of sound, the acoustic “leakage” of mobbing sound “into” a home makes a lot of sense. What I call “surface harassment” is the pressure of sound, the resounding of waveforms, against the windows that open my home to light. Air is all around you. Sound, in air, is all around you, inheriting the properties of air including increased propulsion as kinetic energy rises, and equalization on either side of a window pane.

Sound drifts into your open windows; when your neighbors set up fans in their open windows and set them to exhaust into the narrow breezeway between your two homes, the forced air becomes a gentle propulsion system for sound, even for taunts and insults that mobbers recite based on the false tautology that their words are the sticks and stones that will beat you out of your home. Like the forced air systems of window and exhaust fans, a parametric speaker is a propulsion system for focused ultrasonic sound whose form expresses its own sound pressure. Sound can be shot into a chimney or a rooftop venting pipe; it can be swept along with the heat of a forced air heating system. Sound travels fastest in warm air, stirred by the increase in kinetic energy; when sound moves on cold air, we experience the comparative lack of kinetic energy as a quieting. In the homes where I lodge while working in California, for example, central heating systems often originate in a ceiling crawl space and are therefore easily accessible—and vulnerable—from above, the fans that pump the warmed air through the venting system forcing sound with it. The possibility of injecting sound into building ventilation systems is another reason why drones carrying directional speakers makes sense for mobbing.

Touch has a pressure, and like touch, the pressure of sound can be felt. Hence the concept of “sonic weapons” and a “sonic gun.” Sound is tactile, making itself known through waves that we hear or vibrations that we feel. It is the tactile quality of infrasonic sound that makes us feel it in our chests, that affects us physiologically and potentially with great harm. When the vibrations of sound affect the air and then the bones inside the ear, even those with impaired hearing can “hear” sound. When the victim of mobbing sleeps on her side with her ear to the pillow, the vibrations of infrasonic sound transferred to the structure of her home resound through the bones of her inner ear and ensure that she cannot escape the verbal abuse of the mobbers. To learn more about bone conduction, see the On being mobbed blog entry, Mobbing close to the bone: Bone conduction.

The soft cushion of a pillow absorbs the waveforms. Put your ear to the pillow and you hear the sound of mobbing; take the pillow from your ear and, unable to continue travel over a different transmission medium, the flow of verbal abuse is staunched. Acoustic material dissipates sound by absorbing it or by repelling it. A contact microphone listens to the vibrations of the waveforms. When it comes to single pane windows, a collision with the glass makes sound that travels in one transmission medium fall into the human-audible range. It is the use of an unfamiliar form of sound that makes secret the language of the mob, at least this is what stops witnesses from hearing the verbal abuse of the Seattle real estate mobbers.

Surveillance tools like plane-forming speakers have been around since the 1950s. The reason they work for mobbers is because they are novel. The victims of mobbing cannot make sense of the unusual acoustic experience they have and may become subject to hoaxes that they’re “hearing voices”; the investigators who should aid the victims of mobbing are unfamiliar with the phenomenology that the victim is describing and dismiss victim accounts. This inability to accept the veracity of an unusual phenomenology will cease as beam-focused sound applications become commonplace and we become familiarized to the experience. The inability of investigators to accept the account of victims who are hoaxed and harassed using beam- and plane-focused sound will cease once trends in their criminal application are better reported.

Mobbing is a highly predatory crime designed to deprive its victim residents of their legal home, be they tenants or owners, and its victim owners of the benefits of holding a property. To do it under the noses of the city and the police, and to do it as much as possible without leaving evidence or forensic traces behind. Beam-focused sound imprisons the victim in a sound corridor for mobbers’ delivery of the hoaxes, insults and threats whose utterance is highly illegal. By using beam-focused sound, mobbers provide their victims with an experience so novel that no one believes it could have happened. Even the victim may doubt his perceptions.

Something else I’ve considered is that if there is a dipole system in use between the north and south mobbing houses, for example, or any other means being used to transmit infrasonic sound onto a common slab shared with my home or in any other way that would cause sound to vibrate into my home from the ground up, perhaps the sound would be best heard where its vibration is not dampened, such as on the single-pane windows of this house, or through my pillow in bone conduction when I sleep on my side. If the strategy of mobbing a home and its resident from the flanking structures includes the transmission of any vibration into the earth whatsoever, that would seem an unconscionable act of greed in a fragile and slide-prone area such as this one nestled above the Burke-Gilman bicycle trail and the waters of Lake Washington. I remember hearing how home owners have requested and gotten seismic monitoring during nearby construction projects on these slopes. How does infrasonic sound affect a slide area? Wouldn’t the City of Seattle be concerned about a practice that risks a hillside to gain a single lot?


How does all this relate to the use of soundboard? Soundboard gives you a way to minimize acoustic leakage through your windows. Understanding how sound travels through and around glass, as well as through the seams, joints and vents in your home, gives you a chance to counteract at least some portion of sound-borne harassment. That in turn gives you time to get some sleep, maybe to function better, and maybe even to keep your job. Soundboard may be one of the most valuable countermeasures a mobbing victim can take to hold her life together while trying not to be run out of her home.

First of all, you want sound board, acoustic board, that absorbs sound. You can get this type of material at Lowe’s or a similar building supplier. It’s under $15 for a 4’x8′ sheet. You can have it cut at Lowe’s or use a hacksaw or even a utility knife to cut it at home.

If you’re a new user, you may want to try a tight cut in a few windows in the room you sleep in or the room you work in at home. This alone will probably be a marked improvement over leaving your window panes entirely available to the mobbers. But it won’t last forever. Real estate mobbers know their materials, so they’ll start to turn up the sound, they may begin to use more infrasonic sound or perhaps they’ll begin to batter any areas of light left after you cover the window or to hit the joint between the window pane and the frame.

For this reason, I began to use layers of acoustic material. That allows me to tightly fit a first piece into a window for sleep, and then I might put another over the window opening, leaving a few inches of the soft board overhanging the window frame on either side. This makes it harder for them to exploit an incomplete seam. I try to keep the second pane close to the wall by leaning something against it. This further mitigates the opportunity for the vibration of sound to get to me.

Sound that hits the pane vibrates out in all directions, to the edges of the glass. In other words, when the acoustic board is cut to the exact size of the pane, the sound will pulse to the edges of the glass and may not be sufficiently diminished by the board.

This is probably why the sound of the surface harassment is dampened when I use my silicone pot lids as window ornaments during the days when the south house mobbers try to interfere with my work by hammering the windows. This is a contact method of dampening the vibration that is the sound battering the window; this contact method interferes with sound’s vibration and travel to the edges of the panes as it dissipates.

Even if I cut the acoustic board to fit tightly into a window, I cannot always ensure that it presses against the pane of glass and, by contact, absorbs the vibration of malicious sound. Perhaps this is why also I’ve had the best results with tucking fabric into edges of the window frames after the first piece of sound board. That helps to seal the acoustic board closer to the window as well as minimizing the leakage of air and light, mediums for the travel of sound. The sound fabric absorbs, and if your ear is not against it—in other words, if there is an “air-gap” between you and the fabric—the vibrations will be absorbed without making it to your ear.

Remember, as I described in another blog more than a year back, the mobbers do sound checks to ensure that they can hear the verbal abuse they spew into your environment. This is the only way they can ensure that you will hear it. A practiced harasser will find a way to get around your sound board, even if it means shooting sound into a downspout or using an infrasonic speaker to send vibrations through your pillow. So if sound board alone stops working, don’t just keep buying more of it. Try instead to fill the cracks and to create a better seam between the acoustic board and the window pane. You can insert rolled up socks, cardboard, and even towels around the edges of soundboard to further muffle the mobbing sound and, if necessary, to cover any breaks that exist in the acoustic board itself.

Don’t forget. Be sure to remove the sound board during the day and when you’re not using it. Make sure the home you’re trying to save gets all the light and air a healthy home needs.


As always, this writing is incomplete and may include technical inaccuracy. But I found an informative 2014 article about directional sound in Technologies, “Local Control of Audio Environment: A Review of Methods and Applications.” Perhaps if I get a chance later this week, I’ll use it to better this blog entry. For now, a general citation. You can find it at by the ISSN # 2227-7080. The article was written by Jussi Kuutti, Juhana Leiwo, and Raimon E. Sepponen. ▪





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