In that report there are a number of audio recordings that include whoops, grunts, various vocalizations and other audible noises. I took some time to analyze those recordings and made the following observations....
I gave this recording (http://drop.io/Olypenn/asset/where-s-mommy-loop-82609-mp3 ) a good run through with head phones on, the volume up, no filters applied, and the spectrogram rolling. There's more to this recording than would meet the casual observer's ear. I found there are basically two speakers. Speaker 1 is in the foreground causing the breathing sounds (inhales and exhales) and might actually be more than one person, but it's hard to differentiate simple breaths of air that lack vocal characteristics.
The second speaker is in the middle distant background (as indicated by signal strength) and vocalizes in what I'll characterize as a "mewling" voice, or as others have described previously, a child's voice. I counted the number of syllables uttered by the second speaker and came up with a total of nine in the short 14 second clip (before it begins to loop). The first two are before the first speaker's first exhale (or inhale, hard to tell which). They are very faint and the second of the two is somewhat stepped on by the start of the first speaker's breath. I've labeled those utterances #1 and #2 on the annotated spectrogram at:
After the first speaker's first breath completes the second speaker emits three more sequential syllables. The #3 syllable is higher than the earlier two vocalizations, then the #4 syllable is lower than #1 or #2. Finally the #5 syllable is higher, but still lower than the earliest utterances on the recording.
Speaker 1 breathes again, including a loud exhale through the nose. Then speaker 2 utters syllables 6 & 7, more clearly than any of the earlier syllables. And finally syllables 8 and 9. These are the utterances that most clearly represent the words people seem to hear in the discussion above.
And now for a word about words...
I believe that audio analysis can be fraught with the same challenges that occur in image analysis. Specifically, the human mind when presented with information, either auditory or visual, will attempt to resolve that information into a pattern with which it is familiar or comfortable. And in the case of audio analysis, the harder you listen to something, the more likely your brain is to morph the signal in your ears into something you "think" you're hearing.
So just be cautious when you put the head phones on and don't "over-listen" what you're hearing. Sometimes the monkey's not saying Mommy.
That said, the possibility does exist that this could be an example of a clever mimicry. I posit this based upon the accumulating anecdotal evidence surrounding BF vocalizations mimicking other animals, reports of human voice mimicry, and the research of Mr. Scott Nelson which indicates distinct phonemes evident to his analysis of the Sierra Sounds CDs.
And if I were to allow speculation to run wild, I could conceive that this is a sasquatch attempting to lure the humans out of their tent by teasing them with the call of a human child, in the woods, at 2 a.m. But I'm not ready to go there, just yet.
It is also interesting to note that during the 2008 BFRO expedition to this same area, a voice that sounded like an infant was recorded under similar circumstances.
I took the day off work today to nurse a cold, and used that down time to go through the rest of these recordings in detail. I was surprised to find a good deal more in those recordings than is initially evident to the casual listener. Anyone who's really interested in these type of recordings should get themselves a good pair of head phones and spend some time listening slowly and closely. There's some cool stuff in there, and some of it's kinda weird, too.
Anyway, here's a summary with links to recordings and associated spectrograms. Note that I went though the full collection of recordings posted at: http://drop.io/Olypenn
There are more recordings there than are linked above.
The first recording to look at is the "Departing Knock" recording:
The associated spectrogram is here:
The surprise from this file is the faint whoop just before the wood knock, and the even fainter screech (possibly an owl) after the wood knock. You can see the whoop in the spectrogram, but it takes a real eye to spot the screech.
Next is "Distant Knock and Vocal" at:
The vocalization in this recording is a four tone howl, ascending from the first tone to the last.
"Distant Whoop" is at:
A couple surprises here. There are very faint vocals just before and just after the whoop, but you probably won't hear them without head phones. They barely made a mark on the spectrogram. Interestingly, this whoop sounds very similar to the whoops recently recorded by RCM944 outside Richmond Virginia and posted/discussed in this BFRO Forum thread: http://s2.excoboard.com/exco/thread...hreadid=2147171
Then we have the second "Momma" recording from this collection here:
and the spectrogram is at:
The surprise here was the appearance of three faint mmmm-like hums. The third hum steps on the second "momma" vocalization, indicating these are probably two different speakers.
This next one is a strange whoop recording:
I say strange because it sounds more like a whistle than a vocalization, to me. There's also a deep breath of air in seeming sync with the whistle-whoop which might be from the same source as the whoop. It sounds very close to the microphone, and I would have been very startled to hear a call this nearby.
Next is a dog bark, pair of whoops, and a wood knock:
Nothing extra about this one, but it is a great recording. And if you're really into signal recognition, the first whoop demonstrates "reversed" comma shape that I've seen in a growing number of whoop calls. The descending whoop at the end is a little unusual, not a call I've heard before (but I'm still new to this).
And finally we get to what I think is probably the weirdest, coolest, most interesting recording in this collection. This segment is a little over a minute long and it has a LOT going on in it. But if you don't use head phones you'll probably miss most of the action. The file is here:
And to do this recording justice I had to make 4 spectrograms to capture all the annotations and notes I made.
In the first spectrogram:
the recording starts out with a speaker making some canine sounding barks, but before this spectrogram finishes the speaker takes a strange turn. It's fourth vocalization sounds more like a descending howl that trails off in a faint warbling tone. Hmmmm.
On to the second spectrogram:
In this section the speaker issues a vocal similar to a whimper, then a very soft waivering tone before a two note vocal (you won't hear this without headphones). Still later another soft vocal just before a possible bird call and then ending with a descending moan. Bird twitters appear high in the spectrogram as they start up at this point and continue through the rest of the recording.
The third spectrogram:
I should mention that traffic noise has been audible all throughout this recording, and it is easily distinguishable at the very lowest edge of the spectrogram. At the 40 second mark we have a strange and complex call. It begins with a descending whine/moan, to a short grunt, to a drawn out waivering note. I think these are all produced by the same speaker because this call is, or variants of it, repeat over the rest of the recording. Immediately after this there's a very breathy grunt, as if produced by an animal with a large lung capacity. A few seconds later some very faint vocals, a soft grunt and simultaneous soft vocals again.
Moving on to the fourth and last spectrogram:
At the 54 second point the waivering vocalization returns, again with its simultaneous grunt, and followed shortly by a low murmuring grunt. Then some kind of mechanical click (sounded like a camera shutter to me), and a very weak repeat of the waivering vocal with a simultaneous, descending grunt. At 1:01 we see the start of the strongest waivering vocal signal in this recording. On my very first play through I thought "canine", but then I heard the simultaneous grunt and the manner in which the waiver drops off steeply in its very next utterance. At 1:04 a descending moan starts and slides down in frequency until it transitions into the waivering vocal. This time the simultaneous grunt appears to be absent. But there is a very weak and strange sounding bird warble at the beginning of the call (but I think that's probably a bird in the background).
So like I said, this is one busy and weird recording. If there is more to this recording I would really enjoy examining it. With all that noise going on it seems like the vocalizations weren't going to end any time soon.