Comparison of East Central Ohio Chatter with Sierra Sounds

Here’s what I wrote yesterday about the vocalization that I recorded in East Central Ohio:

Anyway, using Raven I discovered that the file I had recorded had some interesting properties. I got these values from the loudest "bark" from the file, rounded to the nearest 5:

340Hz, 685Hz, 1125Hz, 1470Hz, 1810Hz, 2350Hz, then a plateau at 2590-2670Hz.

This is kind of a strange bunch of values. It looks as if the fundamental is 340Hz, and the next value at 685Hz is close enough to support that idea, but we're missing a value at about 1020Hz, though we've got one at 1125Hz. That’s strange, although I’ll remind you that we just looked at a file with an oddity like that in the previous post.

If the value at 340Hz were the fundamental, here's what the call ought to look like:

340Hz 680Hz 1020Hz 1360Hz 1700Hz 2040Hz 2380Hz 2720Hz

Using Raven again, I measured the small clip available from the Sierra Sounds site called “alberrysbit.mp3”. I got these values from the file (isolating the 2nd channel) at about the .380 second mark (it doesn’t seem right to round to the 5 as I did for the file above -- there’s a lot of wiggle room in deciding where to measure a peak):

274-340Hz 610-689Hz 1038Hz 1294-1378Hz 1811Hz

To me, allowing that we have to “guess” the correct spikes in the range of frequencies for some of the harmonics in the Sierra Sounds file, these are very similar. Maybe not similar enough to be the same sounds -- to the naked ear they don’t sound exactly the same, anyway. But they are pretty similar if you are eyeballing them. The Sierra Sounds file doesn’t have that oddness of a value that seems askew, like the East Central Ohio (ECO from now on) chatter did. It’s almost identical to the hypothetical except for the last value. But it troubles me that this sounds was measured with a fundamental at about 340Hz, same as the ECO file. What are the odds against that happening? It makes your “hoax detector” get all twitchy, doesn’t it? But they don’t really sound that similar.

Now, what would it mean if one sound were not a copy of the other? Why are the voices so similar, even if the sounds they are making are not identical? Wouldn’t that argue against two different hoaxers trying to fake the same sounds (rather than one hoaxer rebroadcasting the same sound and hoping no one would notice)? Wouldn’t that sort of suggest, just as a coyote call will measure about 600Hz in the fundamental most any time you get one, that these were two of the same kinds of creatures?

I also found a section on the Sierra Sounds CD that has chatter and whistles much like the ECO file. I checked those also, and I got these values (Track 5, channel 1 at 6.8sec):

340-433Hz 1378Hz

Not finding quite enough information in that, I checked at the 6.2sec mark and got this:

256-340Hz 693-773Hz 1206Hz

Again, there’s not much to go on there, but you do know this much -- if only those frequencies are represented in the files, they couldn’t have been used to hoax the sounds I recorded. But each of these also apparently has a fundamental at near 340Hz.

Now if you wanted to know why I haven’t done this kind of analysis until now, I really thought that as the guy who recorded one of the files, it would be better to let a disinterested party do it. But so far as I know, no one has stepped up to the plate. I realize there aren’t that many of us into sounds with the technical knowledge and tools for the job, so I shouldn’t really have expected to get out of it. Now that I’ve started on it, I’m troubled already -- we had a known hoaxer along with us, and the calls I’ve been able to compare look remarkably alike, though not identical. But if there is another section of the Sierra Sounds CD with sounds like this, I need to compare those also because that may be where the sounds I recorded came from. And if that turns out to be the case, I’ll be scratching my head trying to figure out who was up on that ridge and what they used to blast the Sierra Sounds CD at us..

By the same token, Ron Morehead, one of the researchers who recorded the Sierra Sounds, says he’s looked through his sounds and has not found a match for what is on the file I recorded. If it turns out he’s right and there are no matches, which goes along with what I’ve found so far, what does it mean that these two creatures, separated by many miles and years, share a very similar voice?