Audio capture

[sasha]

I've been trying for several nights to capture the owl(s) calling from the woods surrounding my house, and finally succeeded. (S)he wasn't as close to the window as the previous night - maybe 100 feet away - but close enough to get a several minutes of decent (not great) audio. These were recorded about 3:30 am, 2018 July 13, Fitzwilliam NH, with a Tascam DR-40 digital recorder through its internal mics.

I've boosted the signal by about 20 db, and I've also clipped out the pauses in between calls to speed things up a bit, since they were coming at at invtervals of 35-40 seconds. And speaking of speed changes: there's a series of high-pitched chirps in the amplified signal that I didn't hear while recording. I wasn't sure if this was an artifact I'd introduced or not, so I slowed down the playback to about 1/3 speed. This was definitely a critter of some kind, but I couldn't tell you what. A mouse? A bat? Some kind of nocturnal bird? The slowed-down version almost sounds like the keening of a hawk. Almost. Also in the slowed-down clip you can hear some kind of rhythmic tapping or thumping, very faint. Again, source unknown - and without slowing down the audio I might never have heard it!

Here's a roadmap of the 2-minute clip:

0:03 - 0.19: three hoots
0:32 - 0:38: variation #1
0:43 - 0:49: (twigs snap - deer walking around?)
0:51 - 0.56 - variation #2
0:57: (another twig snaps)
1:06: final hoot
1:13 - 1:17 (pause - silence)
1:17 - 2:05: 1st two hoots, 1/3 speed, with unknown chirping & tapping audible

TASCAM_0073_2018-07-13.mp3

(1.91 MiB) Not downloaded yet

[mnaz]

Amazing capture. Spooky. Sounded almost like a dog starting to bark when the call first started. You didn't hear the chirps? Interesting. Quite distinct on playback. Who knows what's creeping about in the night...

[sasha]

I wasn't monitoring the recording as it was being captured, & the original signal was about 20 db fainter than what I've uploaded here. I didn't hear those peeps until I'd amplified the signal - and even then I wasn't sure if they were from an external source, or the result of something I'd done to boost the level. Slowing down playback to about 30% convinced me it's an animal of some kind - but since the chirps all seem to come from the same direction, I no longer think it might be a bat. A small rodent, maybe, or a nocturnal insect?

I tried again a few nights later, but only got one distant hoot, and none of the squeaks.

Thanks for listening!