Sounds of Silence

The human ear can only hear a limited part of the sound spectrum. Above that range is ultrasound and below it is infrasound. Although largely unheard, vibrations in these ranges can still affect the human body in ways that are quite different from the informational aspect of simply listening. These higher and lower registers of sound frequencies are, today, the stuff of imaginative speculation. While the conspiracy watchers believe they are the basis of secret weapons research for covert operations, mind control and other conspiratorial uses, another, more idealistic, school associates them with meditative states and magical technology.

Sound is a waveform, with low infrasonic frequencies having a long wavelength that can cover great distances, and with high ultrasonic frequencies having a short wave length. The medical profession, chiefly for diagnostic imaging, employs ultrasound most usefully. Both ultrasound and infrasound are inaudible to humans but can, on occasion, be felt resonating within the body itself. Exposure of unprotected ears to infrasound can also cause an increase in pressure within the middle ear, disturbing the sense of balance.

It is alleged that many feature films, particularly horror movies, employ the use of infrasound to produce a heightened state of unease in the audience. The most recent addition to this list is the film ‘Paranormal Activity’. Perhaps this subtle effect is partly to do with the film’s extraordinary success. The only film to date that is known for a fact to have employed infrasound is the French film ‘Irréversible’. The rolling camera-work as well as infrasound was purposely used to create total disorientation in the viewer. Some audience members found the film so disturbing that they had to exit the theatre. If you ever find yourself watching a film that, on appearance, does not seem so affecting, and yet you are physically disturbed by it, then it might be a simple case of the soundtrack having bursts of infrasound at tense moments.

The natural world is awash with infrasound created by thunder, earthquakes, tsunamis, volcanoes, shifting tectonic plates and even winds. The ability of animals, such as bats and dogs, to hear ultrasound is well documented, but numerous animal species can also hear and utilize infrasound. Elephants have the ability to hear the distant rumble of thunderstorms far earlier than humans can. Other animals may even employ infrasound as a weapon: recent research suggests that tigers are able to deliver a physically stunning roar immediately before attacking. Similarly, sperm whales seem to use pulses of infrasound to stun the large squid that form the basis of their diet.

The use of disconcerting noise to unsettle the enemy is hardwired into most higher animals, from the warnings and battle roars of confrontational beasts to the trumpets, drums, bugles, bagpipes, devilish war cries, taunts and piercing shrieks used by humans in their conflicts. An example that springs to mind is how General Noriega was bombarded with endless cycles of high-volume pop music when he sought refuge in the Vatican Embassy in Panama, as were the Branch Davidians during the fateful siege at their compound in Waco. Similarly, during the Gulf War, in the prelude to the final massacre of the fleeing Iraqi forces on the road to Basra, American soldiers were reported to have blasted grunge and death rock from speakers mounted on their vehicles. Yet in these cases, for all the psychological terror the noise was intended to create, it was a crude application of volume and culturally jarring music rather than the directed application of a sound frequency as a weapon.

Possibly the earliest account in Western literature of sound itself being used as a weapon can be found in the Bible. As detailed in Joshua 6:5, Joshua leads an attack on the city of Jericho (c1400 BC) during which he commands his people, outside the walled city, to remain in total silence for seven days. On the seventh day, seven trumpets made from ram’s horns give a “long blast”, the people shout… and the walls of Jericho come crashing down. It is significant that silence was used as well as noise.

Scientists have developed ways of measuring infrasound associated with these phenomena to aid their research. The military use of infrasound dates back to the First World War, when the detection of such frequencies helped pinpoint the enemy’s heavy artillery. The potential of infrasound to affect the human body has long been apparent; even audible sub-bass frequencies at the correct volume can churn your stomach. The theory behind infrasound weapons tends to focus on the idea that certain frequencies can be used as both a weapon and as a method of crowd control.

It was NASA scientists in the early 1960s that produced most of the documentation of the effects of infrasound on the human body; they were particularly keen to discover how proximity to the low frequencies produced by rocket engines would affect their astronauts, especially during launching. Their extensive tests confirmed that, at certain volumes, infrasound did indeed have various physiological consequences, producing vibrations of the chest wall, changes in respiratory rhythm, gagging sensations, headaches, coughing, visual distortion, and post-exposure fatigue. Subsequent research has determined that the frequency that causes vibration of the eyeballs, and therefore distortion of vision, is around 19 Hertz.  The effects of this specific frequency were confirmed, independently, by the work of engineer Vic Tandy while attempting to demystify a haunting in his Coventry laboratory. This spook was characterized by a feeling of unease and vague glimpses of a grey apparition. A spot of detective work implicated a newly installed extractor fan that, Tandy found, was generating infrasound. Tandy believes that ghost hunters could benefit from investigating the infrasound frequencies at other haunted locales. Not only does this frequency create visual disturbances by vibrating the eyeball – hence the shimmering appearance of apparitions – but the frequency could also stimulate a psychological sense of disquiet (hairs on the back of the neck rising and so forth). Even the drop in temperature associated with spectral manifestations could be an effect of infrasound: “It does not cause a measurable drop in temperature of the air,” says Tandy, but “the effect is caused by a reaction in the body.” Effects like these could also, theoretically, be contributing to sick building syndrome as standing waves of infrasound can be created by architectural anomalies or frequencies set up by electronic devices.

There is good reason to believe, then, that exposure to certain infrasound frequencies could stimulate aggression and exacerbate psychological disturbances. This might explain accounts of temporary psychosis associated with some natural phenomena, such as the Mistral in the Rhone Valley and the Sirocco off the Sahara, the famous winds that are said to create periods of momentary insanity. That certain gusts of wind have infrasound frequencies has been well documented.

According to the Working Paper on Infrasound Weapons produced by Hungary for the United Nations in 1978, the frequency that is thought to be most dangerous to humans is between 7 and 8 Hertz. This is the resonant frequency of flesh and, theoretically, it can rupture internal organs if loud enough. Ironically, 7 Hertz is also the average frequency of the brain’s alpha rhythms; thus this frequency has also been described as relaxing.

Predictably, the media image of the use of infrasound is as a weapon that disables the body and discomforts the mind; however, it has also been discussed in association with enlightened meditative states. The mantras and chants of monks, priests and followers of a variety of religions are commonly believed to have a profoundly calming effect on practitioners just as some musical instruments - like Tibetan thigh bone trumpets – are thought to resonate at the same frequency as the human body, whilst Tibetan singing bowls are believed to trigger specific frequencies in the brain. A significant part of this old mystical technology is the ritual buildings - tombs, chambers, cathedrals and temples - designed to amplify or modulate the resonances created by rhythmic chants, singing or music.

The activity in our brains functions at several specific frequencies so it seems logical that certain frequencies of sound that are harmonics of that neural activity may influence brain-specific activities.  A powerful meditative technique used in the Vedic tradition of India is Primordial Sound Meditation. The practitioner is given a Mantra – Mantra means “vehicle of the mind” and is a specific sound or vibration – which is repeated silently and helps to enter a deep state of relaxation and awareness. Many studies have shown that a regular meditative practice offers numerous health benefits including lowering blood pressure, strengthening the immune system and releasing stress and fatigue. Audiotapes are also available which are designed to stimulate the relaxing frequencies associated with meditative states via a process of binaural beats. These recordings work by sending different frequencies to each ear which, when combined in the brain, produce a therapeutic ‘pink noise’. It may seem that many of us have somehow disregarded the importance of sound and we are ignorant of the power that sound exerts around us. It only takes a modicum of awareness to see that what we cannot actually see with our eye has perhaps a stronger influence on our daily lives than what we can. The human being is a wonderful creation yet we are limited by our own intelligence. We want proof positive before we will believe something, and proof most often means observable fact. We cannot hear most frequencies of sound waves let alone see them.

We might not notice it, but infrasound permeates our daily environment; the weather, the flora and fauna, the buildings and all the machines that surround us all generate infrasound frequencies. The effects may be as unsettling as a ghostly vision, as tiring as the pressure created before a storm, or as invigorating as a good night’s sleep. Disabling forms of infrasound may be used in future wars or to quell civil riots and demonstrations. With important consequences like these, it is unsettling to realize that we actually know far too little about the audio frequencies that surround us.

Comments

I really enjoyed this article! It is really interesting how certain animals have evolved in ways such as infrasound. I wonder why humans evolved not to be able to produce it/not recognize certain forms of it (like when a thunder storm is coming). I guess we don’t have to stun our prey so we don’t technically need it. Also, how interesting about using infrasound in military operations. That kind of freaks me out. It seems so manipulative to use sound against someone. But then again, combat is manipulative....that’s the point. Side note: this reminds me of the movie Phenomenon with John Travolta. I guess you would say that he senses the infrasound of an earthquake. Unfortunately he has a brain tumor that is accelerating the power of his brain. The article also made me think about how humans have evolved away from perfecting our natural senses. That is kind of scary. If anything happens that brings down the comforts of this technological world we have created, how long would we survive? Could we really hunt and gather again? Would we starve because we wouldn’t be able to survive as animals?

When I read this article I became so grateful that I live on an island in the middle of the sea where sound carries on the wind in far less stressful frequencies than what I experienced when I lived in New York City. In the night I can tell the time by the sound of the frogs and crickets. In the daytime I don't need the clock to understand how fast the day fleets from the rooster's crow, past the worker's truck and the children on their way to school, through the mail delivery, the homecomings, the sounds of dinner and back to the frogs. Certain sounds give us stress while others trigger physical desires and calming memories. I think it is most important that we do not drown out the natural sounds with artificial bombardment - that we experience positive effects from whatever we inflict on our ears.

This article does raise a number of questions about so-called supernatural phenomena around us and it's relationship to sound. We can only imagine the number of fantastical, and indeed religious, beliefs that may have arisen to explain such phenomena, when sound may be the culprit.

And we can always learn from observing the creatures around us that are far more sensitive. Birds are reported to have sounded the alarm and fled for high ground moments before the 2004 Indian Ocean Tsunami struck. In Japan, local animals often sense and react to earthquakes moments before they arrive or can be detected by humans.

I am a fan of this article. I think that it is wonderfully specific. It makes me want to make a lot of infrasound experiments. It also makes me think about the fact that MP3 files remove the high and low frequencies in order to have a smaller file size. What are we missing by not hearing those extra frequencies in our music? Are we losing the "mind-shifting" element that music can have by reducing it to only the frequencies that our ears can hear?