Most people would agree that this sucks:

http://www.youtube.com/watch?v=1BPNX9fFWRc

Most, that is. But by no means all.

A couple of my neighbors have these things — high tech subsonic subwoofers or whatever they’re properly called — inside their houses. When they activate them, it causes my house to shake and the air is permeated with what seems like a thick, almost physical blanket of… Of what, precisely? Is it sound? It seems a bit too physical for that, because it’s like, it reaches out and touches. I ran this past M. Simon (who has a background as a sound engineer) and he told me to look up “Infrasonics.”

While there is no Wiki page on a subject of that name, there is one on Infrasound:

Infrasound, sometimes referred to as low-frequency sound, is sound that is lower in frequency than 20 Hz (Hertz) or cycles per second, the “normal” limit of human hearing. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. The ear is the primary organ for sensing infrasound, but at higher intensities it is possible to feel infrasound vibrations in various parts of the body.

If you want to avoid this type of “sound,” ear plugs are quite useless.

Because of the way it reaches out and touched, Infrasound seems to have potential as military weaponry.

Some common bio-effects of electromagnetic or other non-lethal weapons include effects to the human central nervous system resulting in physical pain, breathing difficulty, vertigo, nausea, disorientation, or other systemic discomfort. Interference with breathing poses the most significant and potentially lethal results. Light and repetitive visual signals can induce epileptic seizures (see Bucha effect). Vection and motion sickness can also occur. Cavitation, which affects gas nuclei in human tissue, and heating can result from exposure to ultrasound and can cause damage to tissue and organs.[citation needed]

Studies have found that exposure to high intensity ultrasound at frequencies from 700 kHz to 3.6 MHz can cause lung and intestinal damage in mice. Heart rate patterns following vibroacoustic stimulation has resulted in serious negative consequences such as atrial flutter and bradycardia. [11] [12]

The extra-aural (unrelated to hearing) bioeffects on various internal organs and the central nervous system included auditory shifts, vibrotactile sensitivity change, muscle contraction, cardiovascular function change, central nervous system effects, vestibular (inner ear) effects, and chest wall/lung tissue effects. Researchers found that low frequency sonar exposure could result in significant cavitations, hypothermia, and tissue shearing. No follow on experiments were recommended. Tests performed on mice show the threshold for both lung and liver damage occurs at about 184 dB. Damage increases rapidly as intensity is increased.[citation needed] The American Institute of Ultrasound in Medicine (AIUM)has stated that there have been no proven biological effects associated with an unfocused sound beam with intensities below 100 mW/cm² SPTA or focused sound beams below an intensity level of 1mW/cm² SPTA. [13]

Noise-induced neurologic disturbances in humans exposed to continuous low frequency tones for durations longer than 15 minutes has involved in some cases the development of immediate and long-term problems affecting brain tissue. The symptoms resembled those of individuals who had suffered minor head injuries. One theory for a causal mechanism is that the prolonged sound exposure resulted in enough mechanical strain to brain tissue to induce an encephalopathy.[14]

There was an article in Wired years ago documenting a fatal case of collapsed lungs caused by low frequency sound:

In two of the cases his team describes, the men were standing close to large loudspeakers when they suddenly felt chest pain.

A third case involved a 23-year-old smoker who had suffered several episodes of pneumothorax. During a follow-up medical visit, the doctors mentioned having seen two music-related pneumothorax cases, and the patient suddenly remembered that two of his attacks happened at heavy metal concerts.

Noppen said he and his colleagues suspect that loud music may damage the lungs due to its booming bass frequency, which can be felt as a vibration going through the body. The lungs may essentially start to vibrate in the same frequency as the bass, which could cause a lung to rupture.

It’s probably a good idea, according to Noppen, to stand back from the speakers at concerts and clubs and to ease up on that car-stereo bass. It might also save your hearing, he added.

The idea of using a potential military weapon to induce pleasure is intriguing, as it touches on the sometimes blurry line between pain and pleasure. There are a number of people and organizations now devoted to fighting so-called “boom cars,” which seem to be the “traditional” source of this physically aggressive noise, and in response, the noise (which users crave) is simply being moved indoors:

Extremely loud sound systems in automobiles may violate the noise ordinance of some municipalities. Some cities have even outlawed so called “boom cars”, vehicles containing loud stereo systems that emit low frequency sound, usually with an intense amount of bass. A number of organizations and websites are dedicated to lobbying for tougher restrictions on boom cars, citing that they disturb the peace and cause documented health problems. Noise Free America, a 501(c)(3) non-profit group, cites boom cars as one of the most problematic sources of noise pollution.[15] In 2007, the U.S. Department of Justice issued a guide to police officers on how to deal with problems associated with boom cars.[16] Because of the pressure to ban boomcars, some users have entered the nightclub scene for socialized bass boom atmospheres instead.

That is already happening in my neighborhood. At one point, an officer heard the noise and (not realizing the noise was emanating from a house) pulled over the nearest clueless kid driving a sporty pickup. Unlike ordinary sounds, the Infrasonic blanket is not easy to pinpoint as it is not especially directional.

According to this guy (who has compiled a number of scientific citations), people like it because it produces an endorphin flow:

Although the HI/LF music (sound) may physically hurt a person, they associate the experience with memories of belonging/involvement, fun and freedom. The power they now experience from HI/LF is now more associated with endorphins/adrenaline and not necessarily the earlier quality world pictures. But they may actually be thinking it is related to a normal healthy experience. As Dr. Glasser states in his description of Choice Theory, “…in the case of addictions, seems to satisfy one or more of the ….basic needs” (Glasser, 1996, p.1). A person can actually become addicted to the release of their own natural pain killers (endorphins) as runners do in what I previously described as a runner’s high from the text “Positive Addiction”. Think about how much of today’s music is HI/LF and how people are constantly looking for this type of sound in the CD’s they buy and the concerts they attend. I recently discovered in an audio magazine that there are CD’s for sale that only produce Bass sound. When inquiring, the distributor of the CD’s told me that individuals between sixteen and twenty five years of age are the primary customers for these CD’s. In my discussion with the distributor, I was told that the new digital sound technology on the CD’s can produce lower Bass frequencies than any musical instrument ever produced. He also indicated that some states in the United States have laws that limit the amount of wattage (high intensity) one can have in an automobile. In these states I believe they are more concerned about one’s ability to hear outside traffic and not totally aware of the other physical damage being done by HI/LF (exaggerated Bass) sound. Therefore, one can predict that if this type of sound is withheld, a person my react similar to withdrawing from an addiction. Consistent with this observation is a study done (Fearn , 1972, 1973,) that indicates young people who regularly attend dance clubs and pop concerts show deafness which is dose-dependent upon the frequency of the exposure. Again, if hearing loss is occurring in these situations, then the damage described above (Vibroacoustic Syndrome) is occurring throughout the total body, varying to the degree of exposure. Again, like other addictions, one may actually be subjecting themselves to physical damage and continue on with the addicting behavior.

I’m always skeptical about claims made by activists, but I do think the phenomenon must do something that feels good to some people. Perhaps if as an experiment I sat in a room with one of those subwoofers and treated it like getting into a hot tub I would, um, understand?

I’m at a bit of a loss for words, and I think the most confusing aspect of Infrasound is that our natural tendency is to analyze it simply as a sound. City noise ordinances tend to treat all noise as equal, and judge it in terms of decibels. But with Infrasound, that may be wrong. The original discoverers of the phenomenon noted that it was not picked up by microphones:

Infrasound was used by the Allies of World War I to locate artillery.[1] One of the pioneers in infrasonic research was French scientist, Vladimir Gavreau, who was born in Russia as Vladimir Gavronsky.[2] His interest in infrasonic waves first came about in his laboratory during the 1960s, when he and his laboratory assistants experienced pain in the ear drums and shaking laboratory equipment, but no audible sound was picked up on his microphones. He concluded it was infrasound caused by a large fan and duct system and soon got to work preparing tests in the laboratories. One of his experiments was an infrasonic whistle, an oversized organ pipe.[3][4][5]

Weird. Weirder still is the fact that deaf people can “hear” infrasound about as well as people with normal hearing.

The results from Landstrom et al. are given in [Figure – 15]. It is seen that the vibrotactile thresholds are very similar for the hearing and the non-hearing groups.

Here’s the chart:

Is it sound? Or something else?