Imagine if you will the following scenario: You’re walking down the street and someone comes up to you claiming that we are all surrounded by invisible waves of energy so hazardous to our health that it could potentially make each and every one of us physically sick. Something so dangerous that in 1976 the International Red Cross condemned its use in the military and even the soviets themselves were prepared to ban its use in warfare. They further state that this “Weapon of Mass Destruction” is caused by nothing more than inaudible sound, infrasound to be precise. Clearly, most of us would think that this person is crazy, (and not just because they randomly started a conversation with you on the street), sound can’t make you sick; probably just another conspiracy theorist. Well, what if I told you that this conspiracy may actually be true?
(Elephants are one of the many things that produce infrasound. Source: Ikiwaner / GNU-1.2)
But what is infrasound?
The average human body is capable of hearing sounds of vibrational frequencies between the range of 20-20,000 Hz (cycles per second), and is further able to feel frequencies as low as 16Hz- such as the bass at a rock concert. Sounds with frequencies lower than the normal limit of human hearing are classed as infrasound. Although humans cannot hear or feel it, this silent sound can have a vast array of effects on the body.
Headaches, fatigue, nausea, dizziness, and tinnitus: These are just a small modicum of symptoms attributable to prolonged exposure to infrasound. Though these symptoms can range all the way from a feeling of unease to literal death from severe haemorrhaging of the body’s internal organs.
Low frequency sound waves have a larger wavelength relative to audible sounds and hence have a larger oscillating driving force. This means that the oscillating wave can cause resonance within the bones in our bodies and conduct the vibration to the internal organs. For instance, infrasound with a frequency of around 7Hz may cause resonance in the skull and the pelvic bones - leading to disruptions in the balance centres of the brain and inner ear, alongside interruptions in the nervous pathways that control digestion. This contributes to the strong feelings of nausea and unease in the aforementioned symptoms.
Essentially, it works like how an opera singer (or more commonly a loud speaker), can tune their voice to a certain sustained pitch, in order to shatter a wine glass. Only this time, instead of a glass, it’s your bones and internal organs. Also, if you’re still doubting the effects on resonance on the body, just know the Nazis built an anti-personnel super weapon based on these principles, with an effective range of 100s of metres.
However, as most of us aren’t subject to Nazi super weapons on a daily basis, you may be asking “Where are the sources of said infrasound in my day to day life?”
Answering this question requires many different factors, most notably where you live. But rest assured that all of us are subject to infrasound in some form or another almost all the time. Planes, trains, electric mainframes; lightbulbs, extractor fans, loud speakers, industrial machinery, the list goes on. Though the source of the infrasound does not have to be artificial. Many animals, such as elephants, whales and alligators have developed communication systems via the use of these ultra-low frequency waves.
Not only this, but they are nigh on impossible to escape, for their long wavelength means that their energy is dissipated into the surroundings at a low rate, akin to hearing the bass from a loud car over long distances, without even being able to see the car itself.
Therefore, if you live in the city, you will be, as the “conspiracy theorist” claimed, surrounded by infrasound.
A recent study in the journal Indoor and Built Environment found that many office workers are subject to what they call sick building syndrome. A condition where many office workers complain about experiencing many of the symptoms written above with no clear attributable cause, except that they were in environments with heightened levels of infrasound.
Furthermore, a report in the Proceedings of the Royal Society, suggests that exposure to infrasound in standard working environments often far exceeds the current guidelines of safety, though many perceive this guideline to be too low and archaic.
Moreover, many residents near wind farms, such as in the UK and US, have reported increased levels of what many are calling “Wind Turbine Syndrome”- a condition diagnosed via intense migraines and nausea, thought by some to be brought about by extensive periods of exposure to infrasound generated by the wind turbines. These symptoms reportedly disappear when the residents move out of the area.
Nevertheless, before we vilify wind power we must note that this evidence is anecdotal, and the evidence gathered by a group of experts in the Medical Panel of Massachusetts concluded that there is insufficient epidemiological evidence that these symptoms are caused by the infrasound of wind turbines, as opposed to a placebo effect stemming from people’s perception of wind turbine projects.
On top of this, the vast majority people, although surrounded by many sources of infrasound, are subject to an amount so miniscule, the effects of it are negligible. In addition to this, to do any real harm to your body, the infrasound emitted must by the exact resonance frequency of your bones, with a high enough in amplitude to disrupt your natural processes- which is decidedly unlikely to occur. As such, there is little reason to fear it.
If you’re still worried you may be affected by ultra-low frequency sounds, research has determined that listening to your favourite songs will severely reduce its effects- something that almost all of us do daily.