Is a Knock Just a Knock?

An article written by Randy "Rebelistic" Savig, MABRC Missouri State Director

This is one of those things that at face value seems to be accepted as a typical Bigfoot activity by most field researchers.  Why?  Where did it come from?  The history of wood knock reports go back generations for Bigfoot researchers.  There has been written accounts in newspaper, even some reports that have been collected.  Some of those can be see in the MABRC forums. 

So, if this is an activity of bigfoot, why is it done?  Hunting?  During the day that would make sense.  I could see knocking on a tree to scare a small critter to a smaller tree in hopes of shaking it out of the smaller tree.  But what about at night?  I can’t see that being viable.  Could we be missing something?  We know other primates do this type of thing, why is at this time not been answered, but they do.  We still don’t know if the knock that we hear is wood on wood, rock on wood, or another mechanism all together.  Is it possible that it is a hand clap?  Maybe chest slap?  The reality is that we just don’t know.  One thing is clear.  We hear knocks in areas of bigfoot sightings areas, associated with tracks and possible manipulations to nature so we can’t discount it.  

The sad fact is I had pretty much quit clipping knocks out during audio review because a knock is just a knock, right?  I would log it in the review file, but it wasn’t a cool sound so why bother?

In this article I would like to present what I have found while working with audio that may shed some interesting insight to the topic.  I’ve regularly recorded what we call knocks in many of the areas that member of the MABRC has been researching for years as well as my primary research area.  This article is by no means proof of anything, just what I have been able to come up with using audio analysis in the same way I do when identifying known and unknown vocalizations that have been recorded.  Every sound whether natural, known, or unknown have a signature that can be seen on a spectrogram.  They all have certain profiles, tones, how they start and end that can help identify what the sound is.  Nature allows variables in the sounds as no critter is the same.  However, the structure or signature will still follow patterns of the known sounds.

One of the more interesting things about knocks is that they have different tones to the knock.  You may say “duh” but let me explain what I mean.  In doing the Silent Hills Project it was realized that the sound of the knock comes from the object that we do the knock with not the sound of the tree.  The axe handle we used didn’t change tones when we hit on three different trees.  The only change was the volume, NOT the tone of the knock.  Some were softer, some were louder depending on the softness of the bark or the strength behind the knock.  However, if the handle was held closer to the middle of the axe handle the tone would change.  With that being said, the number of knocks that are reported verses the number of sightings report that are only a small handful that ever say things like carrying a stick or club.  Now if a stick was used to make the sound, you would expect a lot more reports than what is there.  Even the sightings reports that talk “as it disappeared into the woods we heard a knock” sort of thing none of those talk about a club being carried during the sighting.  That brought me to the thought that they could maybe pick up a stick to hit with.  It didn’t take long to realize the problem with that.  It is a lot more difficult to walk through the woods, pick up a stick of any size to use as a knocking stick.  The majority of what is on the ground and rotted to make it useless for more than a pale knock as it breaks.  Nature just claims things back too fast.

For several years I have suspected that for the most part knocks were a way of locating other when they were foraging through an area.  The reason for that was based on drop box recordings where you could hear faint knocks that got louder then soft again.  It was like something came up and passed the recorder and continued until it got too distant to record.  These knocks were not evenly spaced or even the same volume, but it always came together.  Like one knock and a reply a few seconds later almost as one was answering the first one.   It wasn’t until the Silent Hills Project that it hit me that the tones of the knocks would be the same if it was one knocker was doing the knocking.  When I did a spectrogram analysis of the knocks, I was taken aback when it should that there were two different tones to the knock.  Those two tones of the individual knockers didn’t change.  Whether close or far, the tones didn’t vary.  It was easy to see the difference in the frequency (hertz) each knock.  Using that information, we started what we called knock - knock games to try and lure them in.  We have had some interesting results.  Other researchers have over the years had results also by returning knocks and getting responses back.  Here are some links to what we recorded.    

Now if you paid attention to the dates on the three clips you will notice that there were two close together and one a lot later.  The third was recorded in a new listening post we just started to use and a seldom in that area.  If you watch how they evolved, you’ll notice that the knock – knock game changed after the first one.  It was almost like they learned our knock’s tone.  They seemed to be able to challenge us to see if it was one of them or us.  I understand that it is to a lot for folks a big pill to swallow.  I know it was and is for me also.   When I brought it up to some of the MABRC members a couple years ago needless to say I got mixed opinions.  One piece of advice they all basically had was collect the data and follow the evidence.  

Because of the lack of sightings where them carrying clubs or stick, it made me highly suspicious that it was actually wood on wood sounds we were hearing.  Even a rock on wood would not be sensible as there is NO reports of any carrying rocks from what I have read.  I also can not find reports of other primates that carry rock with them as they travel from place to place.  Yes, chimps have been known to pick up rocks and strike a tree for an undetermined reason but the drops it as it leaves.  It is also a rare situation for other primates but knocking sounds seems to be fairly prevalent with Bigfoot.  

All primates have an ability to make a knock like type sound with their bodies.  Chest slap, and clapping are the two.  To my knowledge only the gorilla uses its chest.  But all do clap their hands.  Could that be what is happening that we think is knocking?  With the quick response to our knocks like is recorded it would seem highly unlikely that they could be that quick if they had to swing a stick.  Then you add the rapid one that we caught, it is not possible for us to knock nearly that fast using our ax handle.  Then add the two tones ones and that is impossible using a stick or handle.  

During the Thumperville Expedition with the Western MABRC Team last fall I had them help me collect more data by trying hand claps and knocks from different trees and distances.  We did a simplified version of the of the Silent Hill Project so the folks in attendance could experience the results of the experiment. Here is the baseline knocks for each person there.  

With all the participants using the same ax handle as was used in the Silent Hills Project you can hear they are all a little different.  Hand placement, hand grip used, and even the size of the person using it made a difference.  

In the first field round, we had adults and a young teen doing the knocks.  With the recorded audio it was easy to hear which person was doing the knocking even though they could not be seen.  Each had distinct difference in the tones of the knocking stick and could easily be identified with who it was.  They all used the same knocking stick on the same trees as they went further and further from the recorder.  Even with the volume decrease as the space widened, the signatures on the spectrogram stayed mostly consistent with each person. Here’s the results of the knocking as they moved away from the recorder.  During this portion of the experiment I also had them do a long vocal as a way of showing how the howl/whoop compared to a knock as far as how the different sounds travel.   

Again, notice the different tones each person knocking produces using the same knocking stick.  Even without seeing who was doing the knocking if it was compared to the baseline knocks you could pretty much figure out who it was that was doing the knocking.

We did not do a hand clap during the experiment but with the significant difference with the initial baseline of the experiment it was truly remarkable the sounds of the individual claps among the whole group.  Here are the results of the clapping.  

It is easy to hear the difference between each participant’s clap.  Big hands, small hands, soft and rough all had a different tone.  Now I know that our clapping sounds don’t travel as far as the ax handle.  But with the individual clapper’s tones being so different and distinct, it would make one question if a stronger species with apparent bigger and stronger hands could it travel further if not the same as us swinging an axe handle?  If in fact they do clap to make the sound we call a knock, could their clap be as distinct as ours?  
  

We recently had a night out in our primary research area where we recorded knocks that happened on and off for 3 hours.  No, they were not consistent but in total there were over 50 knocks on the camp recorder alone.   This has been recorded several times in this location and I suspect it is used as location during foraging behavior.  However, there hasn’t been this may in such a short period of time before.  Maybe they were out of sight from each other but not out of sound range?  With some knocks having the same tones that were recorded before my arrival back at camp and may have been done to alert others of people presence.  This was a recording from the camp recorder using the Zoom H2n which have less distortion than my other recorders.  However, you will also hear some camp noise being fire snaps or other man-made audio.  This was a quick cleanup to eliminate as much audio between knocks a possible.  

With the knocks being close to one after another it is easy to hear the different tones of the different knock.  While listening and observing the signatures on the spectrogram it would appear like there is 3 possibly 4 different tones of the ones the recorder picked up.  I highly suspect as with what the Thumperville Experiment shows, that this is more than one critter producing the knock. 

So, what does this all mean?  I’m not sure, but it does seem to point to that each Bigfoot may have a unique tone to their knocks however they are making them.  Could we use this as a way of counting how many individuals are in the area at a given time?  Could we use their distinct tones as a way of identifying certain individuals?  Maybe even track them year to year?  All these questions need to be answered by the bigfoot community if we want to solve the mystery.  Hopefully others will also look at this and see if they can collaborate what I have found.  The answer is in the woods.  Let’s see if we can start putting the puzzle together using a more thorough analysis of the possible evidence. 

Listening

Courtesy of the MABRC

Listen to your surroundings, learn the difference between quad-pedal and bi-pedal walking and learn all the known animals in your area and their vocalizations.

Different sounds can be heard in the woods, recently two Junior Researchers, Splatter and Squish discovered two trees rubbing together that created a whistling sound. At first they thought something or one was whistling at them from the woods, but as they investigated, they discovered the trees were rubbing each other and making the sound.

Learning the difference between quad-pedal and bi-pedal walking can be done by using a parabolic listening device and having a friend or family member walk through an area multiple times while you listen. Then have them walk a dog through the area, listen to the difference in sounds. Continue doing this until you can differentiate between the two.

The researcher should learn to recognize all the local animal vocalizations that they will encounter in their research area. 

The MABRC maintains a large collection of vocalizations in the audio library on the forum. Becoming familiar with these sounds will aid the researcher in distinguishing known animal vocalizations with those usually associated with Bigfoot.

While Bigfoot does have the capability to mimic other animal vocalizations, to be able to determine actual animal vocalizations to that say, of an 800 pound owl or dove making a vocalization is pretty important to the researcher.

Learning the difference between sticks breaking on the ground compared to sticks breaking off trees are also important. Overall, learn the sounds around you, making sure what you are hearing and what is causing it is paramount to conducting legitimate research that is hard to dispute.

Case in point, an armadillo uses it’s snout to sweep back and forth through the foliage and leaf litter looking for insects, grubs and other morsels of food. The sound this creates can be quite unnerving to many in the dark. 

When this occurs to you, it will sound like a Bigfoot walking upon you, and can quite literally send you into a panic if you do not keep your cool.

Call Blasting Protocol

Courtesy of the MABRC

Call Blasting Protocol

While Call Blasting is debatable on it’s effectiveness in the field, MABRC Researchers continue to use it on occasion. From purported Bigfoot vocalizations from around the world, to primate vocalizations, and even baby crying audio.

To conduct Call Blasting and document it for proper review, the MABRC has produced protocols and procedures for researchers to guide them.

Documentation

There are two types of documentation required with respect to call blasting efforts:

* Written documentation.
* Audio/Video recordings.

Written Documentation

The notes or narratives of each outing where sound blasting was performed must include the following details: what happened (a basic log), who was there (names and contact info.), the location (specifically), the terrain, the date, the time-frame, the weather conditions, the history of reports in the area, the accessibility of the area (i.e. legal accessibility, vehicle accessibility), whether there are homes within ear-shot of the call blasting, and anything else that may be scientifically or historically relevant.

Audio/Video documentation

The outing should be videotaped: the people present, the location, the equipment used and anything else that may be historically or scientifically relevant. This record must have someone speaking to the camera, listing the details required in the written documentation (i.e. location, time-frame, local history of reports, etc.). This must be a separate tape from the tapes used to record response vocalizations.

Procedures for Recording Sounds

At least two sound recording devices (which can be camcorders, but preferably high quality digital voice recorders) must be running the whole time the team is on location after dark. The Bigfoot might vocalize before any sound blasting is conducted, so recordings must be made when not blasting sounds.

Do NOT try to record Bigfoot vocalizations by hitting the "Record" button when sounds are heard. Sounds will be missed that way. The recorders MUST be running every moment after dark. Recorders should be started at different times. The recording periods must be staggered so that at least one recorder is running when the tape is being swapped or rewound on the other recorder. A recording plan must be developed in order to do all this in an orderly fashion (include that plan as part of the written documentation). If using digital audio recorders, then using tapes become a non-issue.

If using camcorders, follow this procedure.

Several tapes will be needed for each recording device. Each tape has to be labeled appropriately before it is put in the recorder. Mark the tape with the date and time of the first recording session and each date and time the tape is used after that, if at all. Don't reuse any single tape on more than five outings. Consumer-grade digital tapes have degraded sound after being recorded on a few times. Buy new ones every so often. They are cheap. 

If no responses are heard before a tape reaches the end of its spool, rewind that tape and start recording again. If any sounds are heard while a tape(s) is recording, let it continue to record to the end of the spool, then swap out the tape and mark on the label the time it was taken out of the recorder. Also mark it to indicate that it may have vocalizations on it. Review the tape later, in a dry, well illuminated, relatively dust free location.

Don't ever rewind and replay the relevant section of a master tape over and over repeatedly.

This should only be done with copies or computerized versions of the clip. People ruintheir precious master tapes by repeatedly playing and rewinding an important clip over and over, in order to play it for their friends, before they’ve made backup copies. Don't check to see if a sound was captured on tape while still outdoors. You can check to see if the tape recorded any sound at all, but once you’ve determined that then simply have faith that the relevant sounds were captured as well. You either captured the sound or you didn't. Wait until you are indoors, away from moisture and heavy dust, before reviewing the tapes.

Powering Recording Devices

Adequate power supplies for each recorder will be needed because of continuous recording throughout the night. There are multiple ways for doing this; choices for extended power depend on the recording devices used. Cassette recorders are easiest because they'll go all night on the batteries put inside them. If not, the batteries can be quickly replaced.

Camcorders are more difficult in this regard because the batteries and power accessoriesare more expensive and have a shorter duration. If there are multiple vehicles and cigarettelighter adapters available, these devices can be powered that way. Camcorders will not rundown a car battery. Another option is to have three camcorder batteries for each unit and abattery charger connected to a car cigarette lighter. Yet another option (preferred) is to usedeep cycle batteries with AC/DC inverters. Deep cycle batteries (boat batteries) will last aweek or more if only powering camcorders or cassette recorders.

The Recording Plan

Having a thorough recording plan means knowing the types of devices that will be on hand and having: an adequate number of tapes for each device, an adequate labeling process for the tapes, adequate power supplies for each device, a list of all needed accessories, a plan for staggering the recordings after sundown so that at least one recorder is always running, the knowledge of exactly how long each device will run before a tape is finished or a battery needs to be changed.

Recording devices should be placed several yards from each other and several yards behind the sound blasting gear. If possible, use plastic tote boxes for the recorders. A recorder can be placed on top of a tote box during dry weather and inside the box if the night air gets too moist (with an external mic hanging out from under the edge of the lid). If possible, have an external mic taped to a tripod so it's a few feet away from the recorder when the recorder is in the tote box. In that way, the microphone will be higher in the air and won’t record the sounds of the recorder’s motor noise. 

While recording, have someone with a wrist watch walk up to each recorder every quarter hour and clearly whisper the time near the mic. For example, “It is now 8:15 p.m.”

Microphones

Get the best possible microphones to use with the recorders. Almost all camcorders have jacks for external microphones. External mics are preferable because built-in mics always record some level of recorder motor noise. That noise can be heard when one cranks up the volume of a tape. This is particularly essential when recording faint sounds, because the volume of the tape will need to be cranked up rather high during playback in order to hear these sounds clearly.

No one can be touching the device or the microphone during or after the sound blasting. If the recorders are sitting on the hood or roof of a vehicle, then no one can be sitting inside the vehicle. Movement inside the vehicle will cause loud knocking and creaking sounds on the tape.

If people need to sit inside the vehicles, then the recorders should be at least 30 feet away from the vehicles. The recorders should be at least 30 feet away from people anyway, to prevent their reactions to vocalizations from overriding the recording of the vocalizations themselves. The participants have to be trained and prepared to keep quiet for long enough after any vocal responses are heard so as not to screw up the future usability of any good recordings obtained.

Other Procedures

Triangulation

If possible, you will put people on each side of the ridge or mountain top with walkie talkies. There is no technical process for triangulating the position of a sound source. It's all done by ear and judgment. All of the different listeners simply say which direction the sounds came from. They'll narrow it down greatly that way. Technical triangulation is thwarted by echoes and the relatively limited areas involved.

If you have multiple recorders placed out away from your base area, these could technically become triangulation devices, as you can listen to the sounds being recorded and compare them with the other recorders.

Controlling Distractions

Be as quiet as possible. Do not speak or move after the call blasts. This will help you and your field partner to hear what is going on!

When call blasting, the following procedures should be used.

* Upon arrival, if possible, make sure that no one is in the immediate vicinity that could be alarmed at your call blasting.

* If anyone is in the area, document their location for reference.

* Play the call at half volume, this takes away the majority of the static when playing at full volume and alerting the local Bigfoot that it is a fake call. The best time to call blast is at the top of the hour and every thirty minutes afterwards. This way, if someone reports hearing a vocalization in the area, you can discover whether they heard your call blasting or a real vocalization by what time they heard it.

* You want to play a minimum of 2 calls, and a maximum of 5 calls in any series. Depending on the length of the call being used. The longer the vocalization of your call, the less number of times you want to repeat it.

* Document the time, which direction, what call you used, and what the response was. Have your recording equipment going during the call blasting, as some responses may occur immediately.

* The two biggest problems I have witnessed with call blasting is that the people can not be still. Some one will shuffle their feet and someone will feel the need to talk. This is distracting to those trying to listen and often will be picked up on the recorder over a faint vocal. So as mentioned train yourself to be quiet.
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MABRC Evidence Review Board

The Bigfoot Field Guide staff would like to congratulate the MABRC for putting together their evidence review board, which will examine all in-house evidence submitted by MABRC researchers for peer review.  Eventually we have been told, that non-MABRC researchers will eventually be allowed to submit their evidence for review, and the bigger news that excites the BFG staff, is that other groups have already been contacted about having several seats allotted to them on the board, thereby making it truly a encompassing entity of several groups working together.

Here is the current guidelines for the MABRC Evidence Review Board.

PURPOSE OF THE EVIDENCE REVIEW BOARD

1. The Evidence Review Board (the Board) was created by members of the MABRC organization to serve as a group of experienced researchers to review and comment on possible evidence relating to the existence of a North American cryptid, known as Bigfoot or Sasquatch, based on specific protocols. 

2. It is the desire of the Board to review and comment on various types of possible evidence submitted by any serious Bigfoot Researcher. In the first year of the Board, it was decided by Board members to limit evaluations to evidence submitted by active organization members of the MABRC. In future years, the Board may decide to accept evidence from non-MABRC organization members and from other Bigfoot Organizations.

3. If any MABRC member just wants to release evidence on their own, without the MABRC standing behind it, they are more than entitled to. However. If a MABRC member brings in evidence, and wants the MABRC to stand behind it, it first has to be vetted by the Evidence Review Board. 

4. After reviewing the evidence, the Board will publish a report with an opinion, representing the official opinion of the MABRC. If the findings are remarkable, the Board may release a Press Release.

To check out more about the MABRC Evidence Review Board, check out the MABRC Website and click on the Evidence Review Board tab at the top of the page.