A site dedicated to the review and analysis of potential sasquatch vocalizations, Sasquatch Bioacoustic combines techniques from the domains of intelligence collection, audio analysis and bioacoustic studies to examine the evidence of sasquatch through their vocalizations. ~Monongahela

Monday, August 23, 2010

Something Big Moved in the Piney Woods

This report was originally published June 6, 2010 in the BFRO Discussion Forums.

On the evening of May 15th of this year I had just finished deploying a parabolic mic and recorder in a new area, about a mile east of where I normally set it up and let it run unattended. As I drove back out of the area I decided to stop at a dense piney wood that overlooked two important features of my research area. In one direction it looks over the valley where I normally establish my camp. In the other direction it overlooks the valley where I deploy the parabolic. In past visits to this region I've heard vocalizations from this part of the forest, while I sat by my fire in the valley below. And my parabolic has captured hours of vocalizations from the valley where its normally deployed, and done so consistently over the last few months.

So as the sun was setting I thought it would be a good idea to park my truck along a lonely stretch of abandoned dirt road, deep in a desolate forest, and walk into one of its darkest recesses. I looked at the sky as I walked away from my vehicle and decided I had about enough light for a 30 minute sojourn, so I didn't wear a head lamp assuming I wouldn't get far from the truck.

I walked into the edge of the piney woods and then turned left to skirt along the inside of its edge, keeping to the high ground and allowing the deepest recesses of the piney woods to pass below me, on my right. I seemed to locate a vague passage through the pines (or more properly, red spruce) that had been planted by the CCC about 80 years earlier. The path looked like the remnant of an old logging railway, probably more than 100 years old, which made sense given how the terrain around me laid out.

I followed that wide, level, gently curving path for about 150 yards stopping frequently to listen, attempt an occasional soft whoop, and do a few soft wood knocks with my trusty little-league hickory baseball bat. On the way out along this path I didn't hear anything that gave me any sense that I was not alone and eventually I hit a natural turn around point where brush blocked my way, so I turned back.

I should mention that as I hike around in the woods I've taken to placing my digital recorder in a small back pack that I carry. Extending from the recorder are two sensitive microphones, omni-directional, that I can clip to the shoulder straps of the pack. They're stereo mics so naturally I clip them to the left and right to keep the sound scape properly oriented while I'm recording. I also carry a bottle of water in that pack, and on occasion, hearing an abrupt sloshing sound from directly behind, can be a bit unnerving (especially when your senses are keyed up).

So now I've reversed my direction, and the deep center of the piney woods is on my left. Occasionally I hear a squeak-like sound that I attribute to trees rubbing against each other in the slight evening breeze. I repeat the process on the way out, making soft knocks and subdued whoops, but I can't hear any response when I pause to listen quietly. As I'm closing the last 50 yards to the truck, and crunching along through the leaves of last autumn, I hear a loud and familiar vocalization from the rise of land directly ahead. It sounds like the Big Owl vocals that I've recorded in March, April and now May of this year.

This is where the audio clip below begins. I paused to listen and speaking to myself, make note of the vocal (this sounds crazy, but it helps a lot when post processing audio, the trick is not to be too chatty and avoid stepping on incoming vocals). I hold my position and within a few seconds the vocal repeats, this time it sounds softer but at least its not blocked by the sounds of my foot steps. This is when I start to suspect it is one of the vocalizers I recorded back in March.

I resumed my trek back to my truck, its not far now, and as I walk a third vocal rings out from the high ground ahead. Unfortunately my foot steps obscure it, but by now I'm looking for the relative familiarity of my vehicle. As I draw close, I decide I should do a whoop and wood knock in response to those vocals. I did a moderate whoop first, with no real effect (other than the vocalizer never vocalized again afterward). A short time later I tried a wood knock. Maybe it was the knock, or maybe the whoop and later knock, or maybe my after shave, I don't know, but this seemed to trigger a response.

As I stood quietly, downhill, to my left and deep into the piney woods, I heard something big move in the forest. My ears told me this was large, and as it moved for a few seconds I heard a stick break. The audio recorder heard this as well, and more. I held my position, listening for more movement in the rapidly gathering gloom. None came, and I hear nothing more, but my sense of unease elevated dramatically and I decided it was time to leave a gift and get out. I went straight to my truck, pulled out some Walmart apples and oranges, and left them out of sight of the road before leaving.

This is where I should have held pat, maybe open the tailgate of my truck and sit and listen for a while. But I'd had enough solo squatching for the evening and I just didn't think hanging around would be very productive. So I rode off down the road and checked out a few new locations where I thought I might get some returns to my knocks or vocals.

I've edited the entire 30 minute walk down to under 60 seconds, to focus on the key auditory events of that evening. In addition to the movement to my left, the mics also picked up a substantial grunt/growl from the same direction, and just before the end of the clip, some soft rapid stick knocking sounds, seemingly from somewhere behind me.

The clip, and the transcript are as follows:
(as always, your listening satisfaction will be best from a decent pair of headphones)
0:00-0:02 - my footsteps in the leaves
0:02 - vocalization, obscured by foot steps
0:08 - I say "that was a vocal"
0:12 - vocal repeats
0:14 - "and a second vocal"
0:17 - audio splice
0:20 - vocalization, obscured by foot steps
0:22 - "and a third vocal"
0:26 - audio splice
0:28 - my wood knock
0:45 - stick break and movement from left
0:47 - louder movement from left (slightly audible in right channel, too)
0:50 - grunt/growl from left
0:50-0:57 - light stick tapping possibly from behind (audible in both channels)

Sunday, August 15, 2010

Horn-like Vocals

Personal matters have kept me out of the field for much of this summer, and will do so at least through the end of September. I haven't been back to my study area since the 2nd of July when I downloaded audio from my long duration recorder, then left it redeployed with fresh batteries. I hope a bear hasn't found it and ripped it off the tree by now. It's got another 6 weeks of hanging out before I'll be able to go back and check on it.

But I couldn't stand not having a recorder in the field so I ordered a new one, the Olympus WS-510M, bought a new set of mics from Giant Squid Audio Lab, and went for a hike deep into a regional park not far from my house. I like the looks of this park because its sandwiched between a large river and a sprawling neighborhood of housing developments. The rivers edge is completely undeveloped for miles in either direction and thickly forested with large, old growth timber. There are a number of hiking, biking, and horse trails through the park, but they're closed at night and a lot of the park is strictly bush whacking if you want to get in to see it. The river defining one edge of the park is broad, but wade-able at many places and has several uninhabited islands in mid-stream. On the opposite shore of the river is more parkland, a wildlife management area full of swamps, and miles of undeveloped farm land (as opposed to the neighborhoods on my side of the river).

Its only 20 minutes from my house so I figured, what the heck. You never know until you go. So yesterday afternoon I hiked a half mile in on foot trails and then bush whacked a hundred yards off trail and into a thick understory of white oak saplings. I stopped at the end of a finger ridge that looked out over the heavily forested river bottom. I could hear the river rapids below, about a quarter mile away, and the occasional passing aircraft engine.

I deployed the recorder in one of the saplings with the left channel mic pointed toward the river, and the right channel mic pointed back toward the parking lot where I'd come from. It was about 7 p.m. with plenty of day light left, but before walking away I did three whoop and wood knock combinations.

This morning I returned before lunch to pick up the recorder. The battery appeared to have run out by the time I picked it up, which is the norm. The recorder indicated 14 hours of audio had been captured, so I was pleased that I would have plenty of recording to search through. But when I got it downloaded onto my computer I was dismayed to see that something strange had happened. The recorder captured about 55 minutes of audio, then seemed to pause for a dozen hours, and then continued recording two more hours of audio early this a.m. Not sure why this happened but hope its not a flaw in this new recorder.

Anyway, after going through the three hours of audio it did capture, I managed to locate a couple of interesting clips to share.

The first is a pair of faint whoops that occurred early in the morning hours, right around sun up. They're faint (as are many of the calls I seem to capture), but they were noticeable in the spectrogram software I use to review audio (I would have completely missed these if it weren't for the spectrogram. The first whoop seems to be preceded by a soft wood knock, the repeating down note of a yellow-billed cuckoo appears, and at the end the second whoop sounds nearly the same as the first, just fainter. I put this into a youtube video with annotations to hopefully make it more discernible to your ear (looping the video can help you hear the whoops more clearly):

The second recording might not be a vocalization at all, but its note-worthy enough that I want to share it, and some examples of similar recordings. I call it a "horn" like vocalization. It sounds rather mechanical in origin, but its also very similar to other horn-like vocals recorded by Galahad in Washington State. His recordings sound like a car or fog horn at first, but sometimes waivers in a distinctly biological fashion, sounding natural and not mechanical in origin. The horn-like sound my recorder captured this morning was some time before sunrise, seems to be preceded by a deep wood knock, and also seems to evoke a wood knock response about 15 seconds later (its that wood knock that made me look closer at the possible vocal).

Warning, this horn-like sound is such a low frequency, 265 Hz, that your computer speakers may won't be able to reproduce it (my laptop speakers can't). So head phones are probably required in order for you to hear the note at all (but the wood knock at the end of the clip is easily heard).

Here's a link to the youtube video of this sound in a spectrogram:

And here's a couple of links to Galahad's horn vocals from Washington state, for comparison (these are higher frequency and easily discernible on most computer speakers):

Saturday, August 14, 2010

Sasquatch Bioacoustic Blog Launched

This is the inaugural post of a blog devoted to the bioacoustic analysis of audio signals potentially originating from sasquatch. will serve as the blog discussion locale for audio analysis and bioacoustic musings of recordings collected by contributing members of the informal research community.

Earlier posts from the audio signal collection hosted at will be migrated here for maintenance and discussion.

Thursday, July 29, 2010

Wood Knocks in Communication

I tend to believe wood knocks are used in a range of manners to convey different messages based upon context.

Single loud wood knocks, coupled with a loud whoop or other vocal, could be a "tag-up" if you will. Maybe they ask the question "is there any body out there?!" The wood knock portion of a knock/vocal combination could serve two purposes, the first being punctuation "!", and the second being confirmation (that I am indeed a member of your species, and not some other animal vocalizing in the wilderness).

Softer wood knocks seem to be used as a means of keeping track of each other when in close proximity, and/or when danger may be near. Making a milder warning knock that your buddies a few hundred feet away can hear seems wiser than a loud bash, that would also alert the source of danger to your presence.
Here's a recording that includes a soft whoop, and subtle wood knocks, that might be an example of this kind of situation:

Then even softer knocks may be used for still stealthier communication, possibly when danger is very near, or tension is high. I recorded some fast, soft "stick" knocks just seconds after something moved in the forest near me, and grunted audibly. The knocks sound very tense and can be heard at the very end of this recording:

And then there seems to be the intimidation type of wood knock, which forum member uluax actually observed being made in his remarkable class A sighting from Colorado. I don't have the link to that report handy though.

So in general, I don't think we should attach just one reason or meaning to the existence of wood knocks. Their use is probably more complex than we currently understand, and only time spent recording, studying, and learning them will improve that understanding.

But in terms of a component of communication, the inclusion of wood knocks to enhance vocals is a fascinating advance to consider. A rudimentary technology to be sure, but the mastery of a technology none the less.

Friday, July 23, 2010

A Reoccurring Howl

In the post from June 13th I shared a faint howl that I recorded on the evening of June 12th. The recorder actually intercepted the howl twice, but it was so distant that it wasn't worth sharing both snippets.

But as evidenced in the last few posts, I've been playing around with presentation in the form of spectrogram videos. And I wanted to see just how far I could take it to demonstrate their ability to help audiophiles study sound (and interested onlookers to get more out of the experience).

So this evening I sat down and pulled out the original recording of that faint, distant, flat howl I recorded on June 12th, at 11:13 PM. I applied some heavy filtering to the recording which basically wiped all sound above and below the howl (this worked because the howl was so flat in nature). Then I did the usual noise filtering and amplification, and was very pleasantly surprised by the results. Even listening to it on my laptop speakers, it sounds like a pretty good recording of a howl.

So I took it the next step and played it through my spectrogram software, Sonic Visualiser. As I did so I used "RecordMyDesktop" to make a short video of the spectrogram in action. I loaded that video into PiTiVi, a video editor, and then added my newly cleaned up audio snippet as the sound track. A little tweaking and I had a video ready for loading to Youtube. Here's the result, the brightest parts of the horizontal band of color represents the howl:

But what caught my attention after replaying that howl about 40 times this evening, was a moment when I happened to play another of the Youtube spectrogram videos I've made. That video has a nearly identical howl in it, only captured a few weeks later at sunset on July 2nd. You can see and hear that howl at the 12 second mark in this video:

It comes in apparent response to my whoop and wood knock and before several loud wood knocks toward the end of the recording. It too seems to center around 490Hz and has a basic flat form.

This makes three times that I've recorded this type of howl in my area of investigation. And I hadn't recognized it until I began playing clips and spectrograms from different dates side by side. Obviously my ears and eyes will be much more tuned to that frequency in the future.

Tuesday, July 20, 2010

Walk Up Visitor

In June of this year I deployed a "long-duration" field recorder in my research area. The recorder captured audio over the course of 12 days before the battery finally died. I've reviewed all of the audio from that recorder and found a few interesting items. Among the most interesting was an event that occurred on the fourth night that the recorder was left running in the field.

To me it sounds as if something begins by pelting the recorder with small rocks or nuts. Soon, something begins manipulating the recorder from its left side. Finally, foot steps approach through the crunchy leaf mat and something audibly investigates the recorder. There are no vocals that I can discern, but I can make out individual foot steps, several loud sniffs or exhales of breath, and instances of tapping and knocking (possibly on the recorder itself).

These sounds are best demonstrated in an annotated spectrogram. So I've put together my third attempt and posted it to youtube. The audio and video are a little out of sync, but close enough that you can follow what's going on. Youtube has unfortunately diminished the clarity of the video so reading the annotations can be a challenge, but you should be able to hear & see the important points.

Here' the spectrogram:

Thursday, July 8, 2010

R. Scott Nelson presentation to 2009 Honobia Bigfoot Conference

This video of Mr. Nelson's presentation at Honobia last year underscores the importance of his contribution and the utility of the Sasquatch Phonetic Alphabet to ongoing studies of suspected sasquatch vocalizations.

R. Scott Nelson presentation to 2009 Honobia Bigfoot Conference

This video of Mr. Nelson's presentation at 2009 the Honobia Bigfoot Conference underscores the importance of his contribution and the utility of the Sasquatch Phonetic Alphabet to ongoing studies of suspected sasquatch vocalizations.

A Phonetic Alphabet for the Sasquatch Language

Mr. R. Scott Nelson, a Navy retired cryptologic linguist has undertaken the analysis and transcription of the renowned Berry-Morehead tapes and the purported sasquatch vocals they contain. Several of the most popular sasquatch research websites carry biographic information about Mr. Nelson, and his background clearly demonstrates this authority to tackle such a task as this.

Recently Mr. Nelson completed his transcription of the vocals recorded by Barry-Morehead and through an open letter to the sasquatch research community has shared the fruits of his labor. Significantly, and of great interest to the efforts undertaken here, Mr. Nelson has proposed the Sasquatch Phonetic Alphabet (SPA). This is a vitally important baseline that dramatically enables the linguistic and  bioacoustic analysis of sasquatch vocalizations. It is my intent to utilize the SPA in future vocal analysis and transcription efforts.

And in case you haven't seen the letter from Mr. Nelson, his transcript, the SPA or his video presentation to the 2009 Honobia Bigfoot conference, they are reproduced here:

Fm: R. Scott Nelson
To: Sasquatch Research Community

Re: Sasquatch Phonetic Alphabet (SPA) (attached)

Since I became involved in Sasquatch research a little over two years ago, I have received dozens of e-mails from around the country involving first-hand witness accounts, many containing recorded audio files, of perceived Sasquatch Language. Virtually all of these have included an attempt to spell out Sasquatch “words” using Standard English. This is of little value to the language researcher, since English is notoriously non-phonetic and is subject to widely-varied local dialects.

Since our ultimate goal is the recovery of Sasquatch Language, I have found it necessary to establish a phonetic alphabet and transcription standard (based on the transcription of the Berry/Morehead tapes), by which the contrast and comparison of all future suspected language can be facilitated.

To this end, as an invaluable tool in the future of Sasquatch Language research, I am requesting that the attached standard be published on research web-sites and that it be copied and distributed freely. With this, I am also requesting that local investigators begin using this alphabet as soon as possible to accurately document any perceived Sasquatch Language.

This standard should not be limited to first-hand witness accounts or recordings from North America, but should be used by investigators world-wide, since most languages have many of the same non-phonetic characteristics as English. The work is written in the style of a military SOP (Standard Operating Procedure).

It is my belief that there is nothing more important, at this early stage of Sasquatch Language study, than to standardize the documentation of evidence.

With highest regard for all those engaged in the work of Sasquatch recognition;

R. Scott Nelson
20 June 2010

Fm: R. Scott Nelson
To: Sasquatch Research Community

Re: Sasquatch Phonetic Alphabet (SPA) (attached)

Since I became involved in Sasquatch research a little over two years ago, I have received dozens of e-mails from around the country involving first-hand witness accounts, many containing recorded audio files, of perceived Sasquatch Language. Virtually all of these have included an attempt to spell out Sasquatch “words” using Standard English. This is of little value to the language researcher, since English is notoriously non-phonetic and is subject to widely-varied local dialects.

Since our ultimate goal is the recovery of Sasquatch Language, I have found it necessary to establish a phonetic alphabet and transcription standard (based on the transcription of the Berry/Morehead tapes), by which the contrast and comparison of all future suspected language can be facilitated.

To this end, as an invaluable tool in the future of Sasquatch Language research, I am requesting that the attached standard be published on research web-sites and that it be copied and distributed freely. With this, I am also requesting that local investigators begin using this alphabet as soon as possible to accurately document any perceived Sasquatch Language.

This standard should not be limited to first-hand witness accounts or recordings from North America, but should be used by investigators world-wide, since most languages have many of the same non-phonetic characteristics as English. The work is written in the style of a military SOP (Standard Operating Procedure).

It is my belief that there is nothing more important, at this early stage of Sasquatch Language study, than to standardize the documentation of evidence.

With highest regard for all those engaged in the work of Sasquatch recognition;

R. Scott Nelson
20 June 2010

Phoneme Key

Ä = a in father
Letter = traditional spelling(phonetic spelling)[name]
1. Ä ä = a in father (fäqur), o in mop (mäp) [ä]
2. A = a in can
B = b in bib

4.D = d in did
Ë = a in make
E = e in set
F = f in fife
G = g in gag
H = h in ham
Ï = i in machine, ee in meet
I = i in sit
J = y in yes, i in union
K = k in kite, c in cut
L = l in lull
M = m in mom
N = n in nine
Ö = o in lone
O = o in log
P = p in pipe
R = r in roar
Rr = rolled r, as in Spanish or in Scottish Brogue
S = s in sister
T = t in tight
Ü = u in plume, oo in boot
U = u in run, o in union
V = v in verve
W = w in way
Y = oo in book
Z = z in zebra, s in is
′ = glottal stop
c = tongue click, not evident in BMT
> = phoneme drawn out

Compound Phonemes
ÄÏ = i in like, y in my
JÜ = as in you, u in fume
KH = ch in Scottish loch, x in Spanish Quixote, x in Russian (khah)
SJ = sh in shirt
TSJ = ch in church
ZJ = z in azure, s in treasure
DZJ = j in jail, g in age
NG = ng in sing
Δ (Greek Delta) = th in then
Θ (Greek Theta) = th in thin

Abbreviation Key
(rt) = transcribed at real-time
(75%) = transcribed at a speed other than 50%
(h) = human vocalization
(1-2m) = one or two words or syllables are missing or inaudible here
(int) = interrogative inflection
(dr) = Inflected as a direct response
(imp) = imperative inflection
(w) = whispered
(q) = very low audibility, quiet, almost imperceptible at normal speeds
(im) = human imitating a creature
(ma) = possible male Sasquatch Being
(fe) = possible female Sasquatch Being
(ju) = possible juvenile Sasquatch Being
(G) = grunt, growl or grumble, possible language
(W) = whistle or squeak, possible language
(SN) = snarl, possible language
(SC) = scream, possible language
(TP5) = tooth pop, number in sequence, possible language, not evident in BMT
(WK3) = wood knock, number in sequence, possible language
(RK4) = rock knock, number in sequences, possible language


Transcribed by R. Scott Nelson

Time Utterance

0:4.5 (W) (W)
0:8.62 (W) (W) (W)
0:16.70 WAM VO HÜ KHÖ KHU′
0:18.82 NÄR LÄ
0:21.25 Ü KÜ DZJÄ
0:21.76 FRrÄP E KHÜK LE
0:22.65 ÜN Ï KÜ O GÜ AKH (int)
0:23.85 DÖ WÄÏ NÖ (dr)
0:24.52 MÜ Ï FWI KÖ PÏ KHU′ SJ΄
0:31.43 (ma) HU Ö NÖ> KHÄ HÜ
0:36.95 (ma) FI KÜ ÄÏ> KHÜ′
0:45.03 NE VER GÖ ΄ ÖM KHU′
0:47.03 FÖ WÄ Ï>
0:48.08 WA KHU΄ KVÄM
0:55.34 NÖ ÄÏ ÄKHSJ HÜ
0:57.13 (h) Come on, boy.
0:58.04 (h) Come on, let’s eat.
02.99 MÖÏ PISJ FE KHE KHU′ (h) Come on.
1:11.58 KHU BEK
1:12.63 KHËÄ KHU′
1:13.77 Ä LÄF
1:14.46 MÖ VE KHÜ
1:14.86 LAF KHU′
1:15.35 NÖ KHÏÄ
1:17.49 BÜ GÄ TÄÏSJ KHU′

Monday, July 5, 2010

Sharing What I See and Hear

OK, I want to try a different approach that might help make some of these recordings a little easier to listen to. I have the benefit of some good spectrogram software to use when I'm studying the audio I collect in the field. My ears and eyes are so tuned in to what's happening on the screen and in my head phones, that I often hear things very clearly when in reality they are faint sounds at best to someone listening on their computer speakers.

I don't want to waste anyone's time posting faint recordings that only an audio fan like me could learn to appreciate, but unfortunately my research area is so large that the vocalizers I capture are often at significant distance, a quarter to half mile being the norm.

So this time, instead of sharing a link to an obscure audio recording, I'm going to share a couple links to some short videos of the audio files as they play back in my spectrogram application. These were recorded within the last hour of daylight, last Friday evening, at a remote location in the Monongahela National Forest:

In this first clip I was 200 yards south of the mic and recorder, and could clearly here the wood knock response to my whoop and knock. The recorder captured the response as well, but not as clearly as my own ears could hear it. The spectrogram tells the story better:

About 20 minutes later I was back at the location of the recorder and mic and did another whoop and wood knock. This seemed to elicit still more vocals and several easily heard wood knocks from an entirely different direction than the response described above:

These two videos are my first attempt at this approach and I hope they'll be more effective than just sharing an audio file. Please feel free to comment on the results or offer any suggestions that might make things better.

Saturday, June 19, 2010

Using Your Recorder as a Bionic Ear

During my last outing I took a different approach and positioned myself high on a ridge. I sat there quietly in my truck for about three hours, listening to the night sounds around me. But instead of just letting my recorder roll and listening with my ears the way I have in the past, I took advantage of the quiet (I was out solo) and plugged my headphones into my recorder.

The difference was like night and day. I had my mics positioned up on the roof of my truck, pointing in two opposite directions. I sat comfortably in my driver's seat and listened through the head phones. The mics and recorder functioned just like a bionic ear and pulled in all kinds of faint sounds that I wouldn't have heard using my own ears.

At one point I heard a weird moaning sound, kind of ghostly, somewhere out in the forest. It might have been an owl, but at the time it was certainly a weird sound to hear. And soft stick cracks emerged from all around me as twigs dropped from trees and deer/rodents scurried about.

So if you haven't tried this approach, give it a shot next time you go out recording. When you're sitting quietly, it makes a world of difference (but the noise would probably be overwhelming if you tried this while walking). I used ear buds, and they worked pretty well, but over the ear headphones should do better, if you have them.

Sunday, June 13, 2010

A Faint Howl

This weekend turned up very little good audio. Increased human activity in my Monongahela National Forest research area seems to have put off the vocalizers that I've heard consistently the last few months, or possibly forced them to move out of the immediate area.

I did however find two faint vocalizations while reviewing my audio recordings. The first is a distant, faint howl captured at 11:13PM on June 11, 2010. It's interesting though because its fundamental frequency appears to be about 490Hz, much lower than the typical low end for coyotes. The form is also very flat, similar to the moaning howls recorded from Washington state, and somewhat like the Ohio, Mississippi or Florida howls:


And a video of this howl's spectrogram:

Tuesday, June 1, 2010

Nearing Launch

The web collection of potential sasquatch audio assembled is making steady progress toward its launch date. So far the most significant classes of vocals have been established, and largely populated with audio studies culled from various contributing researchers. Explanatory prose is under development and a domain name may soon be registered.

Sunday, May 23, 2010

Second Trip of the Year - April 2010

On April 2nd I convinced a buddy of mine to join me in the area I've been researching in since last fall. The plan was to visit the previously snowed in camp where I'd spent the night alone back in March, and heard hoots and howls from the ridge above. My friend is very much the BF skeptic, but being a good friend and somewhat open minded, he was willing to play along.

So we drove in to camp before sun down, built a small camp fire, and set about doing an occasional whoop and wood knock combo. Turns out my skeptical friend can do a really fine whoop (something I'm terribly incapable of).

As is the norm, I had my audio recorder set up in the bushes about 50 feet from our camp chairs, where we sat and talked quietly and listened for forest sounds. The left channel of my external mic was pointing north, in our general direction by the fire, and the right channel was pointed south toward a low wooded ridge several hundred feet away.

We didn't hear anything that night that we could make out as a vocal or wood knock. Once, we were fooled by a very chilly frog in a nearby pond. It made a single croak once every 3 or 4 minutes that sounded like a wood knock from the ridge to our south. But we figured it out eventually.

About 11:30, we decided to pack it up and drive back to where we were lodging that night, about 20 miles away. I was disappointed that my friend didn't get to hear anything first hand that evening. I left the recorder going where it was stashed in the bushes, and returned the next morning to retrieve it.

A few days later, upon reviewing the recording from that night, I was surprised to hear a soft whoop and then a wood knock on the recorder. What was surprising was the fact that my friend and I were still in camp, our voices could be heard quietly in the background. It was just 10 minutes or so before we were to drive away from camp, so this took place around 11:25 PM.

The recorder captured a low, guttural whoop that was followed over the next 60 seconds or so by several soft wood knocks. These were captured best in the right mic channel, leading me to believe they originated from the ridge south of our camp. Because they were so close to camp, and well heard by the mic, I was able to amplify the recording and clean it up somewhat to discover other, faint knocks as well. I've cut out a lot of dead space from that 60 second time span and created this abbreviated clip:

Later that night, about an hour after my friend and I had driven away from this research site, the recorder picked up another interesting bit of audio. At about 12:30 AM on April 3rd, several soft but rapid wood knocks were recorded. These aren't the big, loud wood knocks that we often make when out in the field. They're much more subtle, as if meant to be heard by someone within the nearby vicinity. These rhythmic knocks in the middle of the night are something I keep an ear out for now that I've heard them:

Other interesting audio events occurred that weekend, but not as interesting as these two, so I'll save them for another post.

Wednesday, April 7, 2010

The Second Recorder

I wanted to make this second post, a "part 2" if you will, on the results of my first outing of the year on March, 20th. This distinction is useful because on that outing I had a second audio recorder rolling, and its results were better than my in-camp recorder on a phenomenal scale. While my in-camp audio recorder did capture some great vocals and wood knocks as discussed in this other thread: First Trip of the Year - March, 2010, the results from my remote recorder were so extensive that I didn't want to risk confusing the two, and have people thinking that I could actually hear all these other vocals from my campsite location, I couldn't (if I had I probably would have bugged out).

I've posted two dozen audio highlights from a recorder and parabolic microphone which was positioned to the northwest, on the back side of the ridge north of my camp, and in the direction of the original vocals I captured with the in-camp recorder. The access road to my campsite passed not far from where the parabolic was placed in the forest. And the parabolic was aimed northeast, to cover the flanks of the ridge between it and my camp, the floor of the valley below, and the flanks of a large ridge a half mile to the north.

The recordings from the remotely place parabolic are on the same page as the snippets from my in-camp recorder, and can be distinguished by their file names which begin with WS500* (the model of recorder in use). All the in-camp audio files from my earlier post begin with WS310* (*additional numbers deleted). And the link to the audio collection is:

While each of the audio samples includes a brief descriptive text along with it, I'll offer here a few words on why I chose the audio samples that I did.

The first five audio snippets I thought notable because they demonstrate that wood knocks and vocals can occur during the day time. These were captured between 2:00PM and 8:00PM on March 20th. They also show potential for substantiating the hypothesis that wood knocks and vocals may serve to announce the arrival of a human on the scene. Notes next to each audio sample extend this speculation.

Beginning at 9:09 p.m. that evening, the parabolic began to pick up howls, bark, hoots, and much later, whoops, that grew in volume and intensity, before fading away to intermittent periods of quiet. This activity was most intense up until about 1 a.m. that night, but occasional outbursts of the same vocals were captured until as late as almost 5:00 a.m. on the 21st.

Early in the recordings, the vocals are very owl-like, or very dog-like. But the owl is noticeably loud, louder than other owl vocals captured that night. But as time goes by in the recordings, and as demonstrated in the audio samples, the hoots and barks tend to lose their form. By 9:30 the barks occasionally ascend in a slight whoop-like fashion. Not a clear whoop, but losing that canine sound. Also by 9:30, the first wood knocks begin to appear intermixed with the vocals.

There are a series of three or four key audio samples that are most noteworthy in this collection. One demonstrates an association between the bark vocals and wood knocks. Another demonstrates wood knocks associated with the loud owl hoots. Yet another key sample offers the first association of the hoot vocals and the bark vocals with each other (with wood knocks included). An important feature of this sample is the differing tone between the hoots and barks, indicating two different speakers are involved, and each making a unique type of vocal. This is demonstrated again in audio samples from later in the evening, and indicates that the two vocalizers were moving together over the course of the evening.

Based upon the substantiation established in those key samples described above, I carved out a few more interesting samples. Some are better versions of whoop-like barks. Some include faint whoops that you have to listen closely to hear. Some demonstrate a ululating form and other combine howls, whoops, barks and wood knocks all in one segment. And the owl hoots become noticeably absent in some of the later samples. They seem to have been replaced with howl-like vocals.

And at the end of the collection I added a very unique vocal, unlike any I've ever heard before. It's a higher pitched voice, possibly not one of the two speakers described above, and it lets out a short wailing call that sounds to me like "wahoo". It could be an owl call, but I've never heard an owl make a call like that. However it is unusual and I share it for your enjoyment.

Please feel free to share your opinions, good, bad or indifferent. I know some folks won't hear what I or others hear, and that's ok. I want to get all the opinions and angles I can and make this a useful conversation.

Recording Pointers For Beginners

After spending many days last year with my audio recorder turned on, I've realized a few things that have, over time, improved the quality of the recordings I make. With the advent of another season of research before us, I thought it would be useful to share some suggestions, with the hope that new audio recordists (such as I) can use them to get a head start.

The best place to start is with equipment, but not in terms of defining a long list of recorders you should consider. There are other sites and discussion forums dedicated to equipment and their capabilities, so let's not retread that ground. Instead, I'll point to an affordable, entry level rig, that will let almost anyone get into this hobby without dropping too much coin.

My choice of equipment was driven by two things. One, the fact that I'm fiscally conservative, and two, that I've listened to a LOT of bad recordings in my life and along the way learned a little about what made them bad to begin with. So when I set about searching for my new rig I knew that (a) the microphone had to be as good as my wallet will allow, and (b) the recorder should be good, but its not as important as a good mic (post processing can do a little to salvage the impact of a poor recorder, but nothing can improve the hearing of a poor quality mic).

I really didn't want to spend circa $300 on a nice digital recorder such as the Zoom H2 or Edirol R-09. Instead, I wanted to piece together something for under $100, just to see if I could get good recordings out of it. Starting with the mic, I found this hand made gem on Ebay ( ) and purchased it on sale for about $55. Then for the recorder, I searched Ebay again and found that Olympus has a store front where they push all manner of older stock and refurbished new stock. I liked the technical specs of their WS-311m recorder (despite the poor onboard mic performance) and scored one at a remarkable Ebay price of just $35. With shipping, my $90 in equipment came to a little over $100, so I was close enough.

From this point on I'll just try to offer bullet suggestions with short explanations behind them:

1 - Turn On Your Recorder Before You Arrive At Your Research Area - I have missed wood knocks that happened just after I parked and stepped from my vehicle. I wasn't ready, but they were ready for me. That warning wood knock (or vocal) that announces your presence in the area has been reported by more than a few researchers.

2 - Carry A Recorder That Has Lots Of Capacity - I recommend a minimum of 12 hours recording time, both in storage capacity and battery life. The Olympus I describe above can achieve this while recording at "almost" its highest quality level (another important goal). This allows you to turn the recorder on and just let it go. There's really no reason to turn a recorder off unless you know you will be away from a computer for days and unable to offload your recordings (which should also help you justify buying a little netbook computer to take along on your expeditions).

3 - Be Quiet! Give Your Recorder A Chance To Do Its Job - Remember, you're trying to record something living out there in the woods, and you'll quickly learn that your buddies' joshing around is stepping all over those distant wood knocks and vocals that you'll hear in your headphones when you get home. Whenever possible, position the recorder away from the crowd. When in camp, set the recorder outside of camp 50 or 100 feet so that it has a chance to hear more of the woods, and less of the camp (but bring it into camp when everyone goes to bed, you may get a visitor that you'd like to catch on tape). Also, when you're out with the crew on a road hike, try to keep some distance from the most talkative part of the group. And while conversation is encouraged as an "attractive" behavior in these outings, occasionally asking folks to pipe down so you can record that whoop-knock duet is probably ok.

4 - Recording On The Go - It's unavoidable, but you'll pick up lots of noisy interference if you walk around with your recorder. A couple things I've done is to clip the external mics I use (they come with little alligator clips) to my shirt collar, away from my face. That keeps them clear of my body and minimizes some of the handling noise. I've not figured out how to carry a recorder using integrated microphones on my person and do so quietly. Someone suggested a vest with ample pockets and attachment options. That might help, at least to keep it out of your hand. But the sounds of your boots hitting the ground will be an ever present distraction, so try to tread lightly and pause frequently.

5 - Keep Your Directions Straight - If you have a stereo mic, as the one I mention above is, pay attention to which mic is pointing where. When I'm travelling with my rig I keep the right channel mic on the right, and left on the left. That way, if I capture a vocal but am not sure where it came from, I can look at the stereo playback later and possibly determine left or right from the signal strength. I also do something similar when I "post" my recorder outside camp. I point the left channel north and the right channel south. Because they are omni-directional mics they pic up audio well in nearly every direction, except for directly to their rear. Pointing them in opposite directions again helps me know which way the vocal came in from. (If you can, use a compass to accurately determine where north is. This bit of added precision may prove very useful some day, as the post-processing software will be able to make use of that information).

6 - Play With Your Equipment - Get to know your equipment at home before you take it out in the field. Experimenting and learning the fundamentals in your living room is a lot less aggravating than trying to do it in the field. And when you do get out there, you'll be ready to go and not waste any time learning to use your rig.

7 - Establish A Listening Post - When you're out in the field you should be recording all the time. But doing anything with a recorder in your hand is tedious at best. If you put the recorder 50 or so feet out of camp as suggested above, what you've effectively done is established a listening post. But there's no reason why your listening post has to be that close to camp. Consider leaving a recorder out in the field, overnight, and just driving away. Its amazing what you can capture when you're presence is not a part of the scene.

8 - Multiple Recorders - With early success, you may find yourself looking at newer and better recorders and mics. It's ok, don't be ashamed, we all do it. And there are good reasons to do it. For instance, I'm writing this paragraph from the camp chair of my first outing of 2010. I have my original Olympus WS-311m about 50 feet away recording from a tree where I hung it. My second recorder, an Olympus WS-500 is a half mile away, just past the top of the ridge I drove in along. It is outfitted with a parabolic microphone. Thirty minutes ago I heard two loud owl hoots in response to my whistles and wood knocks. The hoots came from the direction of the parabolic mic, so hopefully I'll have two recordings of the same sound in the morning. (Since then I've heard some voice-like vocals moving along the top of the ridge to my north, and a few strange whistles, too. Something might be coming in.)

9 - Turn The Tape Over - Or more precisely, don't let your recordings grow too long. With digital recorders the file size can get very large and make it a challenge to work with on your computer. When I have my recorder with me I try to stop and then start a new recording every 30 minutes or so. This size doesn't tax my computer too badly and minimizes the amount of file parsing I have to do in post processing. Naturally long recordings are unavoidable when you leave the recording rolling while you go to sleep.

10 - Time Hacks - It's always a good idea to mutter a few bits of information into each new recording that you start. For instance, the date and time are very important. You should also mention your location and anything unique about the environment or set up. I often indicate where I am and which direction the left and right mics are pointed in. This may seem an annoyance at first, but a year or more down the line, when you go back to listen through some of the hundreds of clips you'll have collected, you'll be happy that you did take the time to make these comments.

11 - Parabolic Dish Microphones - After you've got a little recording time under your belt, you might be tempted to invest in one of these. They have a lot to recommend them, but they have some downsides, too. First, they can capture and focus the sounds coming from the direction in which you point it, making faint sounds much louder. And if you're recording from a "listening post" over a large area, they can really pull in distant sounds nicely. But the most common parabolic dish rigs are monaural, and not stereo. So you lose the sense of depth perception that stereo recordings can offer (although stereo parabolics do exist and aren't too hard to build). And because of their size they are a challenge to use when on the move, where they create lots of "mic" noise, and pick up more of your hiking sounds and less of the sounds around you.

12 - Wind Screens, To Muffle Or Not - Last year I went a-recording and halfway though my hike lost the wind screen from one side of my stereo recorder. When I listened to the recordings later I was amazed at how great the difference was between a screened versus a non-screened mic. The unscreened mic had more wind noise for sure (but I can mitigate that in post processing), yet its recording was loud and crisp. The channel with the wind screen on it however had disappointing recording performance. It was less windy by far, but it was also muffled. And when I compared recording levels of sounds that had been evenly picked up by both channels, the wind screen often lowered the recording level by 5 to 9 decibels! That's an unacceptable hit to recording levels in my opinion, so I no longer use wind screens, even in the windiest conditions (recording in heavy wind is just a waste of time anyway).

13 - Wait For the Right Moment -
When out in the field, don't bother making knocks or calls while a jet is flying over or an engine is running in the vicinity. If you can hear it with your ears, your recorder can hear it better. And in my experience knocks or calls will very often get faint responses. But your recorder will never hear them because of that jet flying over. Best time to make a knock or call is when it's dead still. And make sure everyone stays quiet for at least 5 minutes after you knock or call. And building on this, the best time to go recording in the field is when the weather is best, a nice high pressure cell with no winds. You'll find the nights can be as clear as a bell and sounds will carry a very long way. So watch the weather channel for high pressure in your area, and never miss a chance to go recording.

These are just some of the things I've come up with in the field, and they've made my life easier. Hopefully they'll help you, too.

Thursday, March 25, 2010

Bark Vocals

In my March 23rd trip report, I mentioned hearing barks every once in a while as I hiked around in the daylight hours. I managed to isolate one of those barks, actually a double bark, from my recordings and wanted to share it as an example of what I kept hearing. The weird thing about these barks is how indistinct they were, I could never get a fix on where they originated from. This example was captured a short time after 10:00 PM:

Tuesday, March 23, 2010

First Trip of the Year - March 2010

My first personal research trip of 2010 turned out to be very successful, from an audio recording perspective. I've posted three pieces of the recordings I made the evening of March 20th.

The first is a couple of loud owl hoots that came in response to some vocals and wood knocks I had made. I respond to the hoots with one vocal bark and three rock clacks. I wood knock is audible at the 20 second mark:

Some time later, in the second recording, a series of whoops has started up on the hill above me. I can't hear the early whoops in this recording at the time, and only heard the loudest whoops at the very end of the recording as I sat by my campfire. The vocal at 1:19 is punctuated with a wood knock:

In the third recording the vocals have turned from whoops into downward "woos" and are farther away from camp. Again, only the loudest of these were audible at the time. Vocals at 0:23 and 0:25 seconds seem to be from two different speakers. A wood knock is audible at 0:26:

Trip Report...

On March 20th I wanted to see if the snow had melted enough that I could gain access to the research area where I recorded wood knocks for the first time, last August. I was about ten miles short of my destination when the road became impassible with deep snow left from the February "double whammy" storms that hit this part of the east coast.

So I turned to my plan B, a visit to the location where I heard (but did not record) a single wood knock as I stepped from my vehicle last September. This area is about 15 miles away from the first, but 1000 feet lower in elevation and less likely to be snowed in. But I was wrong about that.

When I arrived at my destination, I found the last half mile to be about 8 inches deep in snow. No one had driven on the snow since it fell 7 weeks ago, and only one set of boot tracks were laid down, going in, but not coming out. I parked my truck and decided to hoof it in to where I wanted to camp, check out the area, see if I could drive all the way in, etc.

I turned on my recorder before my vehicle came to a stop. I parked next to a truck with Georgia tags, apparently belonging to the boot prints that went hiking down the road ahead of me. I got my gear together and started following those tracks south, into my destination.

Along the way I was trying to listen to my surroundings. I heard a loud wood pecker from time to time. Then I thought I heard a loud bark. I stopped and listened, but nothing. I continued on and some time later, heard a loud bark again. This wasn't my imagination. It was loud enough to overcome the noise of my own hiking filling my ears. But I couldn't tell what direction it came from, it was just too indistinct. I did a lot more hiking that day, about 5 miles all together, and heard similar barks from time to time, but could never nail down their source. I should have some of them captured on audio, and will have to spend some time later to isolate them.

As I reached my turn around point, the bitter end of the driveable road where some partiers had built a fire ring, I noticed the loan hiker's boots continued on along a marked hiking trail that followed a stream down the valley. Later in the day I would follow those tracks. That guy covered some ground.

I ate my lunch by the fire ring and listened quietly. There was nothing loud enough for my ears to pick up, no more barks, but a cursory review of my audio recordings seem to have captured some possible vocals and wood knocks. Again these will bear further scrutiny (I used two recorders that weekend and have 26 hours of audio to plow through).

After lunch I picked up my gear and hiked back out to my truck. I decided the parking location of my truck was a great place to deploy my new parabolic mic for its first field trial. I went north from my truck and dropped down over the roadside and into the woods about 50 feet. I propped the parabolic up on a tripod against a fallen tree and pointed it out over a deep valley and at the ridge a half mile to the north east. This was pointing away from the area I would camp in, and would hopefully capture sounds that I wouldn't hear from camp. My camp position was in the next valley to the south and behind the ridge where I had parked.

Back at the truck I put it in 4 wheel low and carefully made my way up the snowy lane. I had tested the depths and thought with a little luck I should be able to make it through the worst. Halfway through my driving ordeal I look up the road to see the loan hiker returning. He stopped to say hi, I admitted that I was the second set of tracks he saw. Before I could ask if he'd heard or seen anything he seemed in a hurry to move on, so I ended the conversation and plowed ahead.

I got to my camp location at about 2 p.m. and had plenty of time to hike and scope out the local area. I went downstream following the hiker's boot tracks in the snow. After a half mile his tracks kept going, but I didn't. I heard another bark while I hiked back to camp and decided to head down another trail that went into the next valley to the south. I squirrel hunted this valley last fall and saw bear sign there. I was familiar with what I was seeing but wanted to scope it out as a potential recording location. Unfortunately, due to all the snow melt, a roaring stream was running down this valley and completely drowning out any other sounds (an issue the valley I camped in did not have).

I got back to my camp at about 5:00 p.m. and decided to drive out for a dinner at one of my favorite local restaurants. I returned to my camp as the sun was going down and then got down to business. I double checked the parabolic mic on the way in. It was doing fine and recording for all it was worth.

At my camp I parked about 40 feet away from the fire ring in a nice level spot and next to a small boggy area. I was in the center of a narrow valley, about 100 yards wide, and equidistant between the bases of the two ridges that framed the valley between them. The ridges and valley ran east to west, with downstream being to the east. I was at the head water, or western end of the valley. The ridges to the north and south of camp were about 100 feet higher in elevation than my campsite in the valley floor. The nearest houses were 2 miles as the crow flies to the north, three ridges and three valley's away.

As the sun set I put together a campfire and pulled out my camp chair. The audio recorder was hanging in a small tree, near my truck and away from me. But even at that distance, the sensitive mics easily picked up every little sound I made.

The night was mostly clear and a crescent moon would be setting in about four hours. While it lasted I had periodic moonlight illuminating the splotches of snow under the trees around my camp, except for the ridge to the north which was cloaked in dense red spruce evergreens. Unlike the first time I camped alone, last year, I was not feeling quite so unsettled. This was certainly a creepy camp location, but the fire kept things lit up well and I was pretty comfortable.

At about 8 p.m. it was full dark and I started to make a few wood knocks, then some bark-like vocals, then a few rock clacks, and some whistles. I tried not to over do it. I would leave long pauses of space between each of the sounds that I created. I'd been doing this for about an hour or so when I heard two loud owl hoots from the northwest, upstream and toward where the parabolic dish was located a half mile away. They were pretty loud and sounded very owl-like. I had no reason to doubt they were an owl but they did raise my suspicion a bit. So I responded to the owl hoots with a single bark vocal and then three rock clacks. You can hear this in the first recording in the thread linked at the top of this report. (You can also hear a wood knock at the 20 second point, after my bark and before my rock clacks. And no, I didn't make that wood knock).

I heard nothing more so after a bit I went to my truck, got out a beer and a little laptop computer I travel with. I sat down next to the fire and turned my back to the thick forest on the north ridge (the ridge to the south was forested in deciduous trees, but blocked form view by more conifers around my camp).

I was writing happily on an audio recording "howto" that I intend to share here on the forum. It had been about 45 minutes or so since the owl hoot, and then I heard it...

Up on the ridge behind me, maybe a couple hundred yards away, I heard a low "woo" start up and then a second, immediately followed by a hollow wood knock. The affect on me was immediate. Every bit of my senses were focused on that sound. I stopped my typing and listened keenly as two more, louder but short woos came down from the woods above. They had an eerieness to them that told me, "this is no owl", and I smiled to myself as the hair on my arms, neck and head all stood on end.

It was an involuntary smile really, but I think it was in response to the knowledge that I was experiencing for the first time an effect that has been described by so many people on this forum. I felt it was a sort of initiation.

The vocals I heard are captured in the second recording listed in the thread linked at the top of this report. After listening to the recording, it was interesting to find that the recorder captured several low woos and a couple of wood knocks which I could not hear at the time. It wasn't until the final, loudest vocalizations, that I was even aware something was up there. The recording also reveals a wood knock right in the middle of one of the vocals.

I listened intently for more vocals, but nothing else came. Somehow my mind jumped to the conclusion that these woos and the earlier owl hoots were connected, and that my vocalizations and knocks had brought this thing closer to my camp, where I was camped alone, and where no one knew of my location, in an area that had been snowed in for two months until I drove into it. With all that rushing through my mind, I just couldn't bring myself to voice a response to those vocals. I thought the risk of drawing this thing in even closer was just too great given my singular vulnerability.

Hindsight being 20/20, I probably should have made a vocal, just to let it know that I knew it was there. But that kind of reasoning didn't enter the equation. Whatever that thing was, I'm sure it knew I was down there. My campfire smoke filled the top end of the valley and the firelight would have been visible at great distance, even through those dark spruce forests.

I just stayed hunkered in my seat, not moving, just listening. Eventually, after hearing no approaching foot steps behind me, I went back to typing. I kept an ear out for more sounds, but relaxed enough to get my head back into what I was writing. It was some time later, maybe 15 minutes, when I heard the vocals again.

They were lower this time, and instead of ascending in tone, they were descending in tone. And they were farther away, maybe a quarter mile to the east. It seemed that whatever this thing was, it was moving away. It vocalized a few times and then went quiet. Somehow this relaxed me a little. The third recording in the thread linked at the top of this report captures these vocals, and again, my ears only picked up the loudest of the vocals. The recorder captured more, including wood knocks. It's also interesting that at 23 seconds there is a very soft, low vocal and at 25 seconds a much louder, clearer vocal. They sound like different voices, as if two speakers are interacting with each other.

Not long after this I decided it was time to turn in. I climbed into the back of my SUV and soundly locked all the doors. But try as I might, I could not get to sleep. For hours I tossed and turned and imagined that I could hear footsteps outside my vehicle. Twice I had to get out to use the bathroom, and doing so at 5 a.m. was a real exercise.

Eventually the sun came up though, and I was none the worse for wear. I packed up my audio recorder, which was fine at 5 a.m., but dead by 7 a.m. (the temps had dropped below freezing and possibly drained the battery). I was driving away at 7:15 and picked up the parabolic from its location on the way out. It too was dead despite having a lithium battery.

Since getting back home I've been trying to isolate those sound you hear above, and skim through the rest of the audio for any other vocals. My initial impression, which needs closer scrutiny to verify, is that something did come check me out at around 3 or 4 a.m., if the single wood knocks in close proximity to my camp are any indication (I hope to post more on this later). And the parabolic mic seems to have had some luck as well, including a series of low moaning barks in the middle of the night.

As a final interesting aside, I think if you pay close attention to the vocals in the third recording, it becomes evident why some of the old timers called these things yahoos.

Monday, March 1, 2010

Using Spectrograms To Get Even More Out of Your Audio Recordings

Last year I began paying a lot of attention to the various audio recordings of potential sasquatch vocalizations that are available on the internet. And while I have a fairly practiced ear when it comes to audio analysis, I had a sneaking suspicion there is more to these recordings than normally meets the ear. So I set about finding tools that could help me take a closer listen to, and look at, some of these recordings.

The first thing I learned was some new tricks from an old friend, Audacity. I found that with some judicious post processing, as described in this post, I could clean up a lot of noisy recordings and uncover previously obscured or inaudible sounds. The second thing I found was that your ears work better when your eyes are involved. So to "visualize" the sounds captured in an audio recording I looked into spectrograms, and found a free, open source application with audio analysis at its core. Sonic Visualiser ( ) is one of a collection of audio applications capable of generating spectrograms, but in terms of capability and configurability, it's very hard to beat. And the the price is certainly nothing to sneeze at.

The thing that makes Sonic Visualiser so appealing to me, its capability, also created a learning curve that took me a few weeks to work through. But the value of this type of tool, even for the simple act or reviewing your audio recordings, is so immense that I found it well worth the effort. And because I believe this tool can fundamentally change the way you will look at your field recordings, I'm willing to write this direct "how-to" to help you get up and productive with this software as quickly as possible.

Why do this? Because listening to hours of field recordings on the off chance that something catches your ear has become a pitiful activity. Your time is better spent examining the sounds you've captured, and this tool will help you find the sounds you would never have known were there. With spectrograms you'll not only be able to scroll through hours of "visual" audio in much less time than it takes to play it, you'll actually begin to recognize patterns that tell you what kind of sound you've captured, before you even listen to it. So enough hyperbole, let's get to it...

Begin by downloading Sonic Visualiser from the download page at the link above and installing it on your computer. You don't need anything super powerful to run this, but a computer bought within the last couple of years will give you the most satisfactory graphics performance (this is a visual application after all). Older computers will work as well, but with diminishing performance as age increases (hmmm, sounds familiar).

Once Sonic Visualser (SV for short) is installed, you'll want to start it and then open your first audio file. Choose something short for these exercises, just till you get the hang of things. Go to the File menu and select the "Import Audio File" option. In the resulting window navigate to the file you wish to listen to, select it, and click Open.

The file will open in SV's default view, the well known spectrum image. This adds little value to our exercise so click the 'X' in the upper left corner to close that spectrum window. Your audio file will remain loaded, but we're going to view it in a different form, as a spectrogram.

On the keyboard hit the "G" key, which is a short cut to the "Pane>Add Spectrogram" menu item. This will open a spectrogram view of your audio file.

First thing to do is notice the panel on the right of your screen, that's where you'll make all the tweaks to your spectrogram (the configurability I referred to above).

Start by clicking on the tab labeled #2, that will overlay a time grid on your spectrogram. Use the "up" arrow on your key board to zoom in on your file. I normally zoom in until I can see the individual seconds of the file. This zoom will give you good fidelity on the signals that are visible in your spectrogram.

But notice how difficult it is to distinguish the colors of this "default" lime green spectrogram. We can improve this by clicking on tab #3 and from there selecting the drop down menu next to the "Colour" option. You'll see a number of "themes" in the drop down, and eventually you should play with them all and find your favorite. But for now, let's choose my favorite, "Fruit Salad". I know the result is garish at best, but we can make one more tweak to improve that. Just below Colour, select the drop down menu next to "Scale" and choose the dBV^2 settting. This will give you an image with the quiet areas of your recording painted in blue, and the louder portions of your recording painted in increasingly warmer colors (red being the loudest).

Now look at the left hand edge of the spectrogram window. You'll see a range of numbers, high at the top, low at the bottom. These are the frequencies, represented in Hertz, that were captured by the audio recorder that made your recording. From my experience, we'll find most of the sounds we're interested in below 2500 Hertz. So to focus in on that area look in the lower right corner of the spectrogram and note the two short, vertical columns stacked on top of the horizontal bar. (If this is not readily obvious, click the Z key on your keyboard repeatedly. This will toggle the columns on and off. You want them on.) Once you've spotted them, use your mouse to double click the left column. This pops up a window where you can specify the range to view. I leave the first number at its default (the lowest frequency), and change second number to 2500. Click OK and the image will zoom in. 2500 Hertz will be the top number on the left hand edge of the spectrogram.

This is a good spot to give your file it first playback. Easiest way to do that is hit the space bar to start playback (and hit it again to stop). You can also use the buttons on the top menu bar, which should look familiar to you.

As the file plays, watch the vertical bar move left to right across the spectrogram. As it crosses over the "hottest" colors in your file, you'll hear the sound that the color represents. The bright red colors are obvious, and probably easily heard through your computer speakers. But notice all those "warm colors", the oranges and yellows. Those are sounds too. If you pay attention as the vertical bar scrolls over them, they may pop out and become more audible. This is the coordination of eye and ear working together. The eye focuses your attention and the ear picks up the sounds. The more files you listen to, the tighter this eye-ear coordination becomes.

In this spectrogram of a 2009 audio recording from the BFRO expedition to the Olympic Peninsula, vocals audible to the unaided ear are the brightest colors on the chart. But fainter, inaudible wood knocks and vocals also become visually discernible, and subsequently audible, once the ear knows where to listen. These fainter signals might easily have gone unnoticed in a typical audio file review. (click image for larger view)

If you focus on a specific blob of color, notice it's relative vertical position. If it's closer to the top of the image, its a higher pitch sound that your ear should listen for. Conversely, colors at the lower edge are low frequency sounds. This is important to remember because often you'll have overlapping sounds, some high and some low, but a spectrogram can clue you in to their existence (where one might normally obscure the other fainter sound). Eventually, once you can see that two or more sounds exist at one point in time, you'll be able to filter out the louder sound and hear the fainter sound in the background. (Doing this without a visual queue can take a lot of focus thought. This is where spectrograms really start to shine).

That's it, you have the basics down and from here you can do all kinds of experimentation. But before you do, you should save your settings before going farther (or closing the file). That's because SV doesn't automatically keep your settings for you. Every new file you open will have to go through these set up steps (a real hassle if you want to listen to the same file more than once, and who doesn't?). So go to the File menu and select "Save Session As". Enter a file name in the resulting window and click save (try to save this new ".sv" session file in the same directory as the audio file, for convenience's sake).

A couple other things worth touching upon before we go, though.

First, use the left and right arrow keys on your keyboard to scroll forward and backward in your audio file. Hitting the left arrow is a quick way to repeat a sound that you want to "loop".

Second, hitting the "T" key on your keyboard will add a new tab to the panel on the right. When that tab is on top you can click on the spectrogram and enter text labels to next to the sounds you hear. This is a great way of noting neat sounds that you want to come back to, or to highlight for other people who use SV. You can also export all those notes as text, with their time location in the file, and share them in an email.

Third, hitting the "X" key will make the panel on the right disappear, giving you a wider spectrogram to view.

Fourth, everything's better with headphones. If you really want to hear what's going on in your audio recordings, you'll absolutely need a decent set of closed, over the ear head phones (Sennheiser has two or three models from $25 up to $100 or so). Some in-ear head phones might work too, if you can deal with the discomfort.

Finally, to get a real feel for how useful spectrograms are for rapid review of large audio files, load up a big file (preferably something that has been post processed as described in the post above) and scroll through it with the arrow keys. When you see a bright blob on your screen stop, and play through it. When you see a faint blob stop and listen to that, too. That's where the real surprises begin to appear, in the faint signals that your ears normally would have never noticed.

Good luck.

Sunday, February 21, 2010

Using Audacity to Get The Most Out of Your Recordings

Over the last few months I've had the opportunity to review a lot of "wild life" audio which normally involves digital recorders used to capture sounds over great distances. Often these recordings produce faint, noisy results that to the untrained ear possess nothing of interest. But after some looking around and a little practice, I've learned some techniques that work for amplifying weak sounds while filtering out noise to improve audibility. This has allowed me to go back and review hours of recordings that I thought were basically empty, only to discover an amazing amount of very interesting audio. This has proven so useful that I thought it worth while to pass along this information to anyone else who may want to give it a try. So here's my approach to getting the most out of my recordings using Audacity.

Here's what you'll need: the free audio editing program Audacity (download from: , get the 1.3.x beta, it's stable and has the features needed for this work), a reasonably good computer (probably the one you're using now will be fine, I used a five year old laptop for most of my efforts), and a good pair of headphones (over the ear type are best, you don't want stray noise getting in the way).

After installing Audacity, here's the process I use to first amplify, then noise filter, and then secondary filter the recordings for best results.

Open the audio file you wish to edit in Audacity. If you have a long file, multiple hours, I recommend selecting/highlighting about 30 minutes of audio maximum to work with at a time (any more can take a long time to filter). After selecting the time frame you want to work on, click on "File" and then "Export Selection" to export your highlighted section to a new file, with a new name (this step is not necessary if you're working with files that are shorter than about 30 minutes).

Once you've opened the file you wish to edit, it will appear as a "spectrum" in its own little window. Go to the "Effect" menu and open it, then select "Amplify". The entire spectrum will be highlighted and a window will pop up. In that window it will provide a default Amplification(dB) and a New Peak Amplitude(dB). Normally it will automatically choose the amplification needed to achieve a new dB level of 0.0. This is often good enough for our purposes, and you can just click "OK" and be done. The whole file will be amplified. But you can also enter a larger or smaller amplification number and use the "Preview" button to see if you like the result better, then click OK and be done.

Next, we want to use the "Noise Removal" tool. First, click the little icon at the top of Audacity that shows a magnifying glass with a plus symbol in it. This will zoom you in one step for each time you click it. Zoom in until you can see the individual seconds of your recording, left to right across the top of the spectrum window. You want to find a spot in your recording that has the "noise" you want to remove, but has none of the faint background sounds that you want to keep. It takes practice, but you'll be able to spot these areas soon, they're normally the flattest part of the recording's spectrum. Once you've found that quiet, white noise spot in your recording, use your mouse to click and drag across a couple of seconds of that white noise. This will select that noise for use in the Noise Removal tool. Now, go to the Effect menu again and from there select the "Noise Removal" tool. A little window will pop up and at the top you'll see a button labeled "Get Noise Profile". Click it.

Next, on your keyboard, hold down the "ctrl" key and hit the "A" key (Ctrl-A for short). This will select the entire audio file again. Now go back to the Effect menu and select the Noise Removal tool a second time. In the section labeled "step 2" there are three numbers you can adjust. The Noise Reduction number is where you get the most bang for the buck. If it's a fairly quiet file you're working with, then a setting of 6 might be fine. If it's a very noisy file, you might try 12, 18, or even more. But be sure to use the "Preview" button in the lower left corner to see what your result will sound like. If you have the Noise Reduction number set too high, your result will have a "tinny" or metallic sound that is worse than the original noise. You want to select a number low enough to minimize that metallic sound, and high enough to minimize the noise in your recording. After setting the Noise Reduction number, you'll want to choose a number for the "Frequency smoothing" setting. I've always found 75 seems to be a good setting here. And finally, the "Attack/decay" setting, I normally set this to zero as my experiments have found no benefit to any other setting. Click OK and the noise will be filtered from your file.

Next step is to apply a "Low Pass Filter". Go back to the Effect menu, open it, and look way down at the bottom. Click on the Low Pass Filter. The settings I use most often in this window are 6 for the "Rolloff (dB per octave)" setting, the default (0.7) for the "Filter quality" setting, and 2000 for the "Cutoff Frequency (Hz)". Click OK and the frequencies above 2000 hertz will be increasingly reduced in volume by 6 decibels for every octave above 2000. The result is a recording with much of the high end hiss minimized. You might have noticed the "High Pass Filter" on the Effect menu as well. This works similar to the Low Pass Filter, but instead of letting everything lower than the cutoff frequency pass without modification, this will allow everything higher than your cutoff frequency to pass through. The High Pass Filter is useful for minimizing loud low frequency noise, like excessive wind noise on the microphone.

By this point, the Noise Filter and Low Pass Filters have probably knocked the overall volume level of your recording down a bit. So, as a last step, it might be advisable to re-perform the "Amplify" step described above. This should bring the recording level back up to 0.0 dB and make it suitable for basic listening on computer speakers.
Note that we haven't saved our work at any point in this process. Now might be a good time to to do so. But instead of saving it, you'll want to export it. Do this by selecting the "File" menu and then clicking on "Export". A box will pop up where you can enter a new file name (a good idea so that you don't over write the original file). Type in a new name and then hit OK.

As with anything, a little experimentation might improve your results. So feel free to play with those settings discussed above. But for a quick start to getting the most out of your audio files, these suggestions should work for most people.

Now you're done. You have an amplified sound file, with noise effectively reduced, and extraneous high end frequencies filtered out to improve audibility. Now give the file a play back through your head phones. Turn the volume up to a comfortable setting and you should be amazed at how much better the original audio sounds, and how many faint or previously inaudible sounds you can now hear clearly.

Progress Toward Launch

The basic assemblage of researcher contributed audio content has begun. Audio studies are being generated and organized into vocal classes. Much work remains however.

Tuesday, February 2, 2010

New Recording Collection

I've been doing a lot of review and analysis of the recordings I brought home last year. After some careful attention I've begun to find things that I had previously overlooked. A new collection of those recordings is in order, and found here:

Saturday, January 23, 2010

Calls Similar to the Michigan Recording Project

I've been looking for other instances of calls that sound similar to those very human-sounding AAAAHHHH vocalizations in the MRP recordings. Anecdotal sources are a good start, with due consideration of the source, but recordings are always better. From that perspective I've come across the following things that help move those suspect calls toward the realm of possible squatch calls...

First, there's the report from an MRP member of similar recordings made in southern Ohio some years ago, and subsequently reported in local news papers. I don't have those recordings but I'll take the guy at his word.

Second, there's the comment from one of the more experienced members of the BFRO board who reports hearing an identical call in the past. I subsequently contacted that person and was directed to the specific call in the recording. Interestingly, it was probably the 'most" human sounding of all the AAAAHHHH calls that this person had experienced.

Third, there are the guest recordings on Stan Courtney's website which include cries that, while not identical, are somewhat in the ball park of these higher pitched, possibly juvenile, vocalizations.

Fourth, through my growing contacts within the BF research community, I've been privileged to receive access to unpublished recordings for the purpose of examining the audio contained therein. The credibility of these recordings are underwritten by the character of the researchers who generously provide them. And in at least one instance I've heard repeated calls that are similar in nature to the MRP AAAAHHHH vocal.

And finally, I have come across a credible recording of some calls that sound rather similar to the MRP AAAAHHHH vocals, although far more energetic. These are more of a rapid escalating scream with a rapid drop off than the extended calls in the MRP recording. But they possess a very human characteristic to them which further opens the door to some sasquatch sounds being easily mistaken for human vocalizations.

These vocalizations were recorded by John Andrews and Darrold Smith in Washington State. The spectrogram of the calls can be seen here:
and the recording can be heard at the 1:51 point in the 6th recording on this website: