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(BFG Blog) Audio Review…. How to “Know” what you are hearing?

Posted: Sun Sep 23, 2018 5:20 pm
by admin
By Randy "Rebelistic" SavigMABRC Missouri State Director

I have been using audio in Bigfoot research since I joined the MABRC and took it to the woods instead of just at the computer.  As with most of us I had never had audio recording experience before we get into Bigfoot research.  Not having any experience, it really blew my mind at the sounds that were recorded in the woods.  What are normal woods sounds?  What isn’t? What can we do to determine what is what?


I’m not saying this is the only way to do it, but this is what I did and still do.  First is to go into the woods both day and night with your new recorder and find a comfortable tree to sit at and listen.  I found out that it takes about 30 minutes of sitting quiet for the woods to come back alive.  It is truly amazing to me of how the woods goes quiet when a person enters and walks through.  Just sit there with the recorder on.  No looking around.  Don’t play on your phone. Just sit, not moving, even close your eyes so you can focus on listening and wait for the woods to come back to normal sounds. Use the audio as a baseline of what normal woods sounds.  I’ve always been one that I spent a lot of time in the woods throughout the years and thought I knew what the woods sounded like.  I was wrong.  It doesn’t hurt to do this several times as the sounds do change with the seasons.

One really
important thing to remember is our ears can play tricks on us just as our eyes do.  There hasn’t been a time where I have been in the woods where I had a camp recorder running and heard what I thought was one thing just to do the review it is apparent that it was something else. That is one reason that using a camp recorder has such value.  Not only can you use it to verify what you are hearing at camp such as movement around camp, but it keeps you grounded because it also disproves what you thought it was.  Using a camp recorder also gives a way of adding possible evidence to any experiences you have at camp.  The first one that helped give more than just a story was a rock throwing incident that happened a few years back.  Without a recorder at camp this would been nothing than a cool story and personal experience.



I was lucky enough to have a great mentor when I chose to deal with audio.  I was told by MedicDon that the most important things in audio collection.
1. Know your equipment.
2. Use an easy and good audio editing program to review your collected audio.
3. Always, ALWAYS verify with known sounds of nature and known animals.
4. When in doubt…  Throw it out!

Even though these topics could make a long post in their own right, I’d like to touch a little on each of these points. 

There are numerous choices of audio recording equipment out there for people to choose from.  Some like a specific brand for specific reasons.  I have my favorite brands, but it is a personal preference and not what this is about.  No matter what brand you choose you need to learn the advantages and the limitations of the unit.  Not all recorder mics are the same.  If you decide to use external mics, they can really vary, some are mono, stereo, cardioid, powered, etc.  Each have their own qualities and limitations.  Then you add parabolics to it then things even get more complicated.

When I finally decided to build my first parabolic it was a 12” “salad bowl” mic.  No, they are not a true parabolic, but it still does give a lot of directional control amplifying sounds from a certain direction giving adding to the distance of the mics collection.  The way I compared the parabolic to the open external mic recorder was to set them up together.  I hung the drop box external mic set up at the bottom of the parabolic and let them record for a night together.  During the audio review it was easy to see the difference in the spectrogram as far as volume, signature, and contamination levels.  At this point I usually quit using a parabolic in the summer as yes, it is better for hearing further distances, it also amplifies every tree frog and bug in the forest. 

One critical thing in using parabolics is what I call an echo effect.  If the sound comes from the side or rear of the dish it does distort the audio giving what at times sounds like an echo.  When I first ran into that I didn’t know what was causing it and that it was an artifact of recording with a parabolic.  When I suspected it had to do with the dish as the mic didn’t do it when it wasn’t in the dish I did a little experiment.  I set up the parabolic in my yard went out about 150’ from the mic and even though it may sound crazy, I made the same sounds as I walked around the mic.  Now if I had a neighbor see me they would have known
I was nuts!  To try and keep the tones, volume, and to take out any variances, I walked around singing “Row, row, row your boat”!  It may sound funny or stupid, but it was an eye opener for me.  This is what I’ve been willing to do to get to know my equipment.  Any new additions to your equipment I would highly suggest doing this kind of thing to learn your new equipment.

Each of my recorder setups whether drop box with external stereo mics, to drop box with powered external mic, to 12” parabolic, 36” parabolic, to the H2n.  Each record different and has benefits depending what you are trying to accomplish using your audio.

 

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My second
point is being able to use editing software for audio review.  Why is that important?  The plain fact is our ears do play tricks on us.  If you are in the woods trying to record possible Bigfoot vocalizations, guess what?  You can easily interpret things wrong.  We can’t help it, it happens to all of us.  Personally, I use Audacity.  Primarily because it is a free download and easy to use. There is a quite a learning curve to learn it but once you do the filters and other parts of the program help immensely especially the spectrogram.  Each vocalization and sound has a signature.  Each has consistent way that the sound and form that does not change.  When using the spectrogram during reviewing new audio makes it easier to identify known sounds and vocals.
When first using the spectrogram, I used the gray scale as made it easier to see the signatures and learn to read the spectrogram.  After getting used to seeing the signatures I switched full color scale as it is easier to see how the signature is formed as well as volume changes in the vocalization as it is being formed.  It is easy to see if vocalizations are possibly moving.  Once you get to where you identify signatures of known animal vocalizations even when there is distortion do to echoes or ambient contamination, it saves time in running filters of what would otherwise be unidentified by hearing it only.  When reviewing hundreds of hours of audio a year, time does make a difference.  Audacity also makes it easier to clip out possible Bigfoot vocals to either clean up and post or to save in a file for future comparison.  In science repeatability of possible vocals can add a lot of weight to prove that it was not just some anomalous vocal cause by distortion of the audio.   


The third
point is probably the most time consuming especially when you first start.  Where do you find verifiable recordings of known animals?  YouTube? Other researchers?  Those are better than nothing, but many times I have listened to stuff from YouTube where the author of the video says it’s a bobcat and it is a fox.   Us researchers are also at fault in doing this if we haven’t done our due diligence.  Just because it sounds weird doesn’t make it a bigfoot because you were out looking for one.  More arguments and bitch sessions have started because of that than you can shake a stick at.
The places I use the most is college sites, animal research centers and zoos.  Yes, a lot of them are on YouTube but you must stay with reputable sites.  What I have done is make a file with the known sounds and spectrograms to use as a quick reference that I look at during audio review if I have any doubt of a sound or vocalization.  To collect comparison audio I keep it simple.  I have often plugged into the headphone jack on the computer into the mic of the recorder and recorded whatever vocal I am wanting to collect and send that file to Audacity.  Once on Audacity I can either take a screen shot of it or make a short video screen capture so that I always have the audio and spectrogram together.  I store all these in a file for easy access.

That works great for animal vocalizations in the woods but what about the other sounds that we hear in the woods that could be attributed to possible Bigfoot?  Footfalls, rock clacks, knocks, movement in the leaf litter are all things that we hear in the woods and are so easy to misidentify.  One amazing audio clip I heard shortly after joining the MABRC was one that TEXLA http://www.texlaresearch.com/  collected. It was of a possible Bigfoot coming up to a recorder and licking it where the entering bipedal footfalls, the licking sound, coughs, and the exit was all recorded.  They had put peanut butter on the recorder as a draw and this time it had results.  You can check it out here. http://www.texlaresearch.com/coughing_sequence_5-4-08.mp3

This is one of those real grey areas in audio collection that can easily make us post this as evidence without doing the proper home work to insure it isn’t a known critter.  So, I hear movement in the leaf litter what now?  First you must try and figure out if it is four-legged or two.  Deer can even sound bipedal if they step in their own tracks.  What I did was head out to the woods and set up a recorder and went for a walk around the recorder.  I also made the effort to record walking from about 100’ from the recorder, passing by the recorder, and another 100’ past it again to see what the limits of the recording distance of my footfalls could be heard.  The fall is the best time to do this as the leaf litter is fresh and easiest to hear.  What I do when I hear what I think is bipedal walking is listen to it several times and try to listen to the ground
.  Sound weird?  You’d be surprised at how many times you can hear rocks hitting hard hooves.  There is also how you can hear the size of the foot by the sound it makes in the leaf litter.  The bigger foot the more leaves are crunched in each step.  There can be other subtle clues also that can be heard if you take the time to really listen.
I also did that with knocks and rock clacks to get a baseline of the structure or signature of the sounds.  This is how the whole Silent Hills Project started.  Different types of sounds travel different distances.  When dealing with skeptics, being able to provide a baseline with known sounds goes a long way towards ending unnecessary arguments.  I can’t count the number of times I have heard the line “I know it was this or that because I hear it all the time”.  Again, our ears do play tricks on us. Arguing doesn’t make a stronger case for us.  Evidence does.  Having a file of baseline sounds keeps us grounded which brings me to the next point.

The fourth
and final point of this post is when in doubt, throw it out!  There is no bigger hit to your credibility and the Bigfoot Community than posting possible bigfoot audio evidence that is easily dismissed because it’s a known critter or sound that could have been prevented by you doing your due diligence.  The only thing that will make it worse is if you argue it without some baseline evidence.  The sad truth of the matter is you can post 100 good things and 1 bad and folks will only remember the one.  That just seems to be the way it works.

One thing that I do want to point out is that I never actually throw out anything when it comes to audio.  I have kept all the raw data that I have recorded since day one.  If at any time someone wants to hear the context surrounding any possible audio clip I have the data for verification or authentication.  If I have a doubt on a sound or vocal I clip it and put it into an “Unknown File”.  If that sound or vocal repeats or is recorded clearer at a time in the future I have it there for comparison. One such occurrence that I had with this is early in my research I recorded what I thought was something handling my drop box.  However, there was no footfalls and virtually no sounds before or after it.  Even though I was super excited and wanted it to be my TEXLA moment, it wasn’t.  I kept the clipped file and hoped for another that would back it up.  Low and behold, a few weeks later it was recoded again.  But this time there was definite wings buzzing before and after the recording.  It was a bug crawling on the external mic.  Luckily at that time I was pretty computer illiterate, so I never posted that as possible Bigfoot playing with my recorder.  Lesson learned.  When we are trying to help scientifically prove the existence of Bigfoot it is vastly important to be able to back up our evidence and show repeatability.  That can not be done if we don’t do our homework.

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Source: https://bigfootfieldguide.blogspot.com/ ... ts/default