Do you know exactly how long you have in a noise saturated environment before you reach the point of no return and have irreparable damage to your hearing? (You DON’T want to guess on this one…)
Can you inflict massive damage on an intruder or attacker using a single sound?
Do you know how to protect your home from these types of attacks or even normal every day “road noise” in order to make you and your family’s everyday life…just a little more livable? This is part four in our series on “Using Sound As A Weapon.” This article describes where to find sonic weapons, sound protection and sound isolation equipment and materials. Read below to find out more:
Sonic Weapon Products
Other than the high end hailing sonic devices—selling for as much as $30,000 each, most devices for homeowners are dedicated to getting a threat sick and disoriented such as those shown in Figure 1 and Figure 2 below.
Images via Information Unlimited
I won’t discuss the companies that produce long range hailing devices for the military and law enforcement markets – I’ll focus on the homeowner market only. After extensive research, I found six companies that sell sonic weapon products to homeowners. These companies and some of their products are listed in Table 1.
Sonic Weapon Products
Additional products can be found by accessing the companies referenced in in the table above.
I believe that between the price points of the $440 PPF40 and the $30,000 LRAD long distance acoustic device (and beyond this price point) are a number of sonic products that have been developed for military and law enforcement use. These products are kept secret from the general population and have specific uses not shared with ordinary people—including the destruction of matter and flesh.
For most of us, the product lines mentioned in Table 1 are the tools we are sold to protect and defend ourselves and our loved ones. This makes the intelligent understanding and use of sound waves critical in our personal survival.
Exposure Time Limits
Scientists have studied sound for years, and we now know a great deal about the number of hours and minutes intense sound pressure can be sustained by the human body. As sound levels increase there is a point for each person where you can no longer function –or even live. It’s important for you to know these points.
There is a limit to everything, and so it is with sound. Table 2, shows how long you can endure various intensities of sound [or noise] before your body experiences physical damage.
Noise Exposure Time Limits
The 80 dB sound of a garbage disposal truck – can become noisy if the sound persists. However, listening to 80 dB sound can be endured for over 25 hours without harm. It’s when sounds become louder than 90 dB that hearing damage can occur. This is why the government restricts how long you can work in loud environments without special headsets to protect sensitive eardrums. Notice in Table 2 how fast the acceptable time exposure decreases as sound levels increase.
Physical pain can be felt at 140 DB and can be tolerated for less than a second. In the movie, “Under Siege” an actor is shown standing near an 8” battleship gun when it is fired. The concussion from that explosion knocks the actor off his feet (simulated in the movie of course). There is a scene in the movie, “Lucy” where she creates a shrill sound so loud and penetrating it takes down all the other humans in a hallway. Sights such as these are preconditioning us to know what is possible.
Duration of exposure to sound pressure is serious and you should be aware of the effects loud sounds can make on your body. There are essentially three ways to protect yourself from loud sounds—increase the distance between you and the sound source, find a way to block the sound pressure waves, or find ways to absorb or attenuate the sound. (A fourth method is to stop the sound from being generated by the threat.) Since you may not be able to increase distance, sound blocking and sound absorption are your standard choices for handling loud sounds.
Sound Blocking Products
Naturally you want to prevent undesirable sound energy from getting into your home or shelter. You do this by blocking direct air pathways and by placing obstacles in the way to break up sound waves. Everything around you should be considered including where you locate your house.
The earth is a great resource for blocking sound. Homes constructed in quiet valleys or depressions are natural choices as are earth berms that cover part or all of a home. If you’ve ever entered a cave or mine, you know how fast outside sounds are blocked.
Some communities use sound blocking or sound abatement walls to keep road traffic noise from reaching nearby residents as shown in Figure 3.
Fig. 3– Sound abatement wall blocks road noise.
Airport runways have sonic walls where the sounds of jet engines can be reflected upward and away from people working in the area. A sound blocking wall is also used on aircraft carriers during the launching of jet planes. You can adopt similar designs to block as much sound before the energy gets to the exterior of your home. Figure 4 shows all-weather sound panels.
Fig. 4– Acoustiblok All Weather Sound Panels. Image via Acoutstiblok
Figure 5 shows a noise barrier fence to isolate your backyard from neighborhood sounds.
Fig. 5– Acoustifence Noise Barrier Fence. Image via Acoustiblok
Exterior or interior acoustic blankets and walls can reduce sound by over 40 decibels. Interior panels can absorb 85% of noise trying to pass through wall material. A thick mineral fiber material can block 100% of all sound depending on the frequency.
Take steps to seal openings where sound can enter your home. Anyplace where air can get in is a path for sound waves. Consider insulation, gaskets, caulking, and even draft catchers. Stop the sounds at the perimeter to your home before they can penetrate your living space. There are products that can help. Table 3 shows sound blocking products currently on the market.
Insulated foam is another product that is effective in sound reduction.
Fig. 6- Sound blocking panel.
The 1.5” x 4’ x 8’ polystyrene board shown in Figure 6 is sold by Lowe’s for $26 a sheet. Some homeowners use this to construct a sound barrier around noisy portable generators.
Dual and triple pane windows are also good for reducing sound penetration.
Fig. 7- Dual and triple pane windows also reduce exterior sound.
Sound Absorbing Products
Once you’ve blocked all the sources for sound entry, your next line of defense is to absorb as much of the remaining noise possible. Here’s where sound absorption comes in.
Sound Absorbing Products
Products from Acoustiblok, Acoustical Solutiions, and Soundproofing Company can make your home much quieter. There are other manufacturers with good sound reduction products, but these three are the most often mentioned.
Insulation like that shown in Figure 8 can be installed in walls and ceilings to reduce sound and block thermal heat transfer.
Fig. 8 – Wall and ceiling insulation.
The sound protection methods described in this article can work well as long as you aren’t exposed to a high intensity sonic weapon that can penetrate walls and destroy materials and flesh. Should such a weapon be used, your only recourse is to quickly bug out to increase the distance between you and the source before being exposed. Remember, low frequency sound has a long range reach. If you can’t get away, God help you, since there is no earthly protection against low frequency, high intensity sonic weapons. And they exist.
Sound can heal. Sound can harm. And sound can kill. It depends on the pressure wave and who controls the sound generator. We’d all like sound to be used for good. However, there are groups who would use sound to force their own agendas. They present a risk to the rest of us. As you prepare, be ever vigilant, and become the most informed you can be. Knowledge can be your best survival tool.