Hello, I have used acoustic monitoring for bat studies before, but this is my first time using Audiomoth, and using a device that can record both human-audible sound and bat vocalizations. As such, it's been a learning experience to dial in my device settings so that they are optimized for bats.
I am currently trying to use the device in Michigan, where most bats have calls in the 25-75 khz range. A couple species of interest have the strongest part of their calls (characteristic frequency) in the 40-45 khz range.
I currently have the device configured as follows in an attempt to get mostly bats:
And I am recording bats, so that's good! But I'm also recording lots of non-target noise. I get a lot of recordings that look like this (wav file also attached).
Which I'm assuming is just orthopteran noise. Those pesky orthoptera! Anyway, there is rather a lot of it, and I'm wondering if anyone has suggestions to dial in my settings (or for settings when expanding/splitting files) so that I can reduce this stuff and save fewer noise files? I've only done passive acoustic monitoring with Anabats, and that was a long, long time ago, but I don't recall getting quite so many noise files. Thanks for any thoughts!
Try experimenting with these files in AudioMoth Play - https://play.openacousticdevices.info. You can try out the filter settings on the recordings and check their effect. Using the recording above, if I increase the window length to 32 samples, this makes the frequency band narrower and it no longer triggers on the orthoptera. It will likely still trigger on the bats at a slightly high frequency.