A Case for Infrasound


Most researchers of the sasquatch phenomenon soon recognize that many people have strange reactions to the presence of these animals. The feeling of being watched is by far one of the most frequently mentioned anomalies in reports, but there are many others. It is my opinion that infrasound can account for most, if not all, of the seemingly inexplicable reactions.

Dog whistles and bats emit sounds that are too high in pitch to be heard by the human ear, but there are also sounds that are too low in pitch to be heard. These sounds are respectively called ultrasound and infrasound. The prefix “ultra-” means above, while “infra-” means below.

The pitch of a sound is the frequency that the sound wave is vibrating, and is measured in Hertz. Basically, this is how many times a second the sound wave wiggles. Normal human hearing can detect sounds between 20 Hz and 16,000 Hz.

Experiments by the US military and others indicate that infrasound can have profound psychological and physical effects on humans and other animals. Humans exposed to various frequencies of infrasound have reported disorientation, nausea, fear, panic, sorrow, loss of bowels, drowsiness, visual hallucinations, chills, high blood pressure, increased blood flow, internal respiratory problems, and even organ damage. The US Navy reports that it is unsafe for humans to be exposed to infrasound at a level of 140 dB. It is reported that infrasound can rupture organs and make objects explode, and it is a matter of history that there has been research into sonic weapons.

Not all infrasound is damaging. In fact, you are surrounded by sources of infrasound. Some natural sources of infrasound are waterfalls, ocean waves, earthquakes, and atmospheric phenomena like thunder and lighting. Even audible sound waves can interfere with sounds of other frequencies and cause an infrasonic interference wave. Most of these naturally occurring sources of infrasound emit noise that is of a very low level, or “loudness”.

Many animals use infrasound for various purposes. Elephants use infrasound to communicate over vast distances. Whales use infrasound to navigate the oceans, much in the same way that dolphins use ultrasound to do the same. It is also known that whales, like dolphins, use sound waves to stun and catch fish. Tigers have infrasonic frequencies in their roars that seem to serve to confuse or stun their prey as well.

Sasquatches might use infrasound for these very same reasons, and likely others. Being a wide ranging species that would often be separated from others, it would be beneficial to communicate by means of infrasound. Infrasound is not as readily absorbed by trees as are sounds of higher frequencies. In fact, infrasound can travel directly through trees and even the ground, theoretically enabling sasquatches to communicate with others of the same species on the other side of a hill or mountian, far out of hearing range of normal vocalizations.

Field observations by myself and others indicate a strong relationship between sasquatches and ungulate herds, their most likely predominant food source. Being large animals, it would take a tremendous amount of calories for a sasquatch to run down a deer or elk, even if they are cooperative hunters as has been suggested. It is at least possible that sasquatches can focus infrasonic waves at prey to confuse or disable it in the same way that tigers and whales do. There are certainly many stories of deer acting very strangely when a sasquatch was thought or observed to be nearby. These deer may be suffering the effects of an infrasonic “blast”.

Clearly sasquatches do not like being in the proximity of humans. It is widely reported that humans do not like this much either, and this is likely not an accident. It seems like a logical evolutionary adaptation of the sasquatch to develop strategies to repulse humans, and infrasonic warning “growls” might be a very effective way to keep us strange, bald cousins away. These “growls” might not even be audible, but they could be accompanied or covered by an audible vocalization.

I once had a strange experience that could have been the result of this possible repulsion adaptation. In the summer of 2004, I was on a solo expedition to Bluff Creek, CA. In my exploring, I found a water source off the beaten path and near a ravine that, according to the locals, was haunted. I was exploring the vicinity of the water source when I found a series of broken trees along a game trail. There were four tree breaks between five and eleven feet off the ground. Each break occurred where the game trail abruptly changed directions, and each of them was broken in the direction of the turn in the trail. At the end of this zig-zagging path was a faint, but clearly visible large foot-shaped impression in the loosse forest duff. This path was also the way to move towards the water under the thickest cover. Excited about the prospects of this new location, I went back to my car to prepare camp. When I got back to the vehicle, I was suddenly very nervous, and just wanted to leave, which I proceeded to do. I went to a nearby lake and experienced no furthur emotional disruptions. At that point in the trip, I had been camping alone in the area for almost a week (if you’ve never been to Bluff Creek, it can be a very spooky place). However, when I decided that I had to leave this new spot, I still had a couple hours of daylight before dark. I do not adamantly claim this was the result of infrasound, but I do file it away as possible data supporting that hypothesis. I will say that some of my best and closest possible sasquatch encounters were at this location, but over the next two years after I returned with a partner.

In sasquatch research, I am what’s known as a “flesh and blood” guy, meaning that I think sasquatches are (fairly) normal animals. Some researchers think they have something to do with the UFO phenomenon, and sometimes believe that they have supernatural abilities of some sort, such as telepathy. These beliefs are substantiated by some very strange things being reported from witnesses, and especially repeat witnesses. Commonly reported “weird” things include witnessed suddenly falling asleep, supposed communication with the sasquatch via words or more often feelings, paralysis, and even strange blue or white lights being seen in the vicinity of sasquatches. Every one of these has already been mentioned in regards to possible effects of infrasound with the exception of words in one’s head, but that doesn’t seem too unreasonable if one is overcome with a deep feeling of unwelcome. Humans very often think to themselves with words, though not always.

Infrasound has been shown to be present in areas widely considered to be haunted, and indeed many places frequented by sasquatches have the same reputation. I do not claim to know much, if anything, about ghosts and the investigation thereof (I’m just a bigfoot guy), but research has been done to suggest that the infrasonic frequency of 19 Hz could be responsible for many ghost encounters. Considering infrasound can cause visual hallucinations, it doesn’t seem unreasonable to suggest that this could be part of the reason that strange lights are sometimes included in sasquatch reports.

I have never seen lights of this sort, nor have I been subjected to the deeply unpleasant possible effects of infrasound, but my research partners have, a couple times while I was nearby. Once, again in Northern California, my research partner saw light blue lights darting through the woods on the hill above us. A Native American man told us a similar story from the exact same location, though we did not solicit nor talk about lights of any sort with him until that point. He only mentioned the lights because we asked him about bigfoots.

I have heard the stories of other investigators being unable to move while listening to bipedal walking around their tents. One researcher I am aware of actually had lasting physical side effects after a very close encounter where she felt her entire torso vibrate while hearing nothing. Her lingering health problems went away after several months.

As investigators into the sasquatch question, it is up to us to try to verify the hypothesis that sasquatches employ infrasound. The best way to verify this is to look at the wavelengths of vocalizations, hoping that, like tigers, sasquatches have infrasonic frequencies buried in their other vocalizations. This presents some obvious problems. First of all, most recording gear is made for humans, so this gear isn’t designed to accommodate sound waves that humans aren’t able to hear. Secondly, without seeing the sasquatch vocalize, one cannot be sure that the recorded sound is a sasquatch vocalization.

Recording gear that can “hear” infrasound is currently being used to study elephants’ use of infrasound. An excellent microphone to use for infrasonic studies is made my Earthworks Precision Audio. There are several models available with the most sensitive reaching down into the range of 3Hz. These microphones are omnidirectional, which means they record equally well from all directions, not just from the direction the microphone is pointed. Of course, these microphones are not cheap. They cost somewhere in the $1200 to $1500 range.

DAT recorders are a good option for the field recording device. DATs are generally small and light, and can often be powered by rechargeable batteries or run off of other power supplies. The sounds are recorded onto digital audio tape (DAT), and would later have to be transferred in real time to digital format for analysis, but the size and convenience of DAT recorders often makes up for this hassle.

Other digital recorders compress the recorded sounds and thus lose information. Do not use any filtering, noise reduction, or compression when recording, and always verify that your recorder can handle infrasonic frequencies.

Another cheap, yet cumbersome alternative to these digital devices is the use of analogue cassette and reel-to-reel recorders. Cassettes are cheap, but inaccurate. Reel-to-reel tapes are expensive, but very accurate. Cassette recorders are small and portable, while reel-to-reel recorders can weigh over 20 pounds. Still, if you car camp and have one of these buried in your garage, it might be an excellent way to gather infrasonic data. One would still need to transfer the analogue sounds in real time to digital format for precise measurement.

To address the second problem of not being sure that the vocalization recorded is from a sasquatch, consider this: no comprehensive survey of North American animals’ use of infrasound has ever been done. Any recording of infrasound from any North American mammal is potentially significant.

For most sasquatch researchers, the price and hassle of obtaining equipment for recording infrasound will prohibit them from trying this novel avenue of research. It is hard enough to obtain decent recordings of possible vocaliations without the introduction of recording sounds one cannot even hear! I would encourage the average researcher to take copious notes in the field, observing not only what is in the surroundings, but taking special note of one’s emotions and thoughts. Even after one retires for the night, note the sounds outside of your tent, and the feelings you experience, especially when strange sounds or events might be occurring in or around camp. While this form of data will be far from convincing to scientists, it does add a small amount of information to the “maybe” pile. Perhaps patterns can be determined that can help those with the proper equipment obtain useful, quantifiable data in the future.


Back to Articles