Acoustic ecology

s21825 · 2024-04-07T22:33:19.870Z

I’ve been dabbling with an AudioMoth for bird surveying in my area. I set it to record for a few minutes at dawn each day. Then I process the audio files using BirdNet software (GitHub - kahst/BirdNET-Analyzer: BirdNET analyzer for scientific audio data processing.) which analyses the audio and identifies the bird species from their songs. It seems to work very well so far. I’m not very organised yet, but my hope is to start monitoring somewhat regularly throughout the season to start to see which species are present and when they arrive/leave each year.

I hope to try to detect bats too some day, but I haven’t figured that out yet. I think the BirdNet software might be able to do that as well, but I have not attempted to do that yet.

tristan_louth_robins · 2024-04-07T22:45:04.369Z

@fellowfinch (and any others here): if you do get stuck with vast troves of data and need some assistance cleaning/tidying and processing useful stats from audio data, please reach out via DM or e-mail. I’m more than happy to help out!

fellowfinch · 2024-04-08T14:40:33.500Z

thank you so much and I’ll definitely need some help in the near future!

just got my audioMoth in the mail and tested it out a bit and was surprised how the microphone is rather decent for such a small device. I’ll have to check the guide on gitHub for more serious deployments, but just a question for audioMoth users: did you find a good way of reducing wind noise? any windshields that might work for such a small device?

I’m using it with the Open Acoustics audioMoth case.

tristan_louth_robins · 2024-04-08T23:11:34.227Z

fellowfinch:

just a question for audioMoth users: did you find a good way of reducing wind noise? any windshields that might work for such a small device?

I’m using it with the Open Acoustics audioMoth case.

Although I’ve been using using these devices for the past 2-3 years I haven’t yet used the official enclosures (aside form the underwater one.) I am aware that mic self-noise from the wind can be a bit of an issue with the cases, but it’s been my impression that the protective membrane which sits over the pinhole mic can attenuate some of this interference. If the wind is blowing directly onto the case (as opposed to shearing across it), I would suppose - much like other forms of wind attenuation - that some degree of wind distortion is inevitable.

If it’s helpful at all, maybe you could cover the case in a small windjammer? Similar to the type for handheld recorders. However, any rain or dew might present some problems

My alternative case for the AudioMoth consists of using small O-ring containers, drilling a hole where the mic is and covering this (from the inside) with sellotape. Wind distortion is minimal, but I believe some of the mid-to-high end is compromised, especially in quieter conditions. It’s still good though and I’ve stuck with it. These customised cases have survived some abominable winter conditions, but to be honest it took a bit of refinement (and losing an AudioMoth in the process) before I struck the right combination of materials.

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antipodean · 2024-04-09T01:00:42.093Z

@tristan_louth_robins @fellowfinch I’m a total novice in this space but am hoping to deploy some Titley Chorus devices next week. The Chorus mics have a small wind shield but are a lot more expensive than audiomoth (borrowed mine from uni). I’m also concerned about wind noise but read this morning that a high pass filter can be used to remedy. I’m assuming this is applied following collection. Perhaps you could try DIY a wind shield for the audiomoth case using some low density foam?

tristan_louth_robins · 2024-04-09T01:39:21.938Z

Yes, high pass filters can work to take the edge off wind interference, but I guess it depends on how much the wind is cutting across the frequency spectrum. More sophisticated noise removal algorithms (like RX’s suite of tools) can be applied, but then you run the risk of losing transient details, etc. Might be worth doing a search of the adjacent Field Recording topic here on Lines for potential wind attenuation solutions?

Let us know how you go with the Titley Chorus device! I haven’t had the opportunity to use one of these yet.

zoundsabar · 2024-04-09T01:47:58.024Z

I use some wind socks that I got on Amazon for my quad AudioMoth setup. They are a big improvement over no wind protection. They can just barely fit over the official plastic AudioMoth case, but work equally well over the bare AM:

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Movo WS-G9 Furry Outdoor Microphone Windscreen Muff for Portable Digital Recorders up to 3" X 1.5" (W x D) - Fits the Zoom H4n, H4n PRO, H5, H6, Tascam DR-40, DR-05, DR-07 and More (Dark Gray)

Amazon.com

widdly · 2024-04-09T05:49:09.943Z

I sometimes think about the relationship between doing field recordings and plein air paintings. In both cases the results are often secondary to the transformation in your perception. Both create a deeper bond with your environment. And both have made me into a bit of a bird nerd. It is tempting to fixate on the paintbrush or the microphone, but they are not really the important part.

I love this project…

frogid.net.au

Home

Welcome to the Australian Museum FrogID project

fellowfinch · 2024-04-09T20:18:15.718Z

Tried something similar today with a windshield from my H6 recorder. It barely covers the enclosure, but it can be done.

For testing purposes I put the whole AM into the windshield and am gonna see how it works tonight/morning - I’ve set it to record the dawn chorus on top of my AC unit

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Also have you noticed any difference in audio quality recording from the barebone AM and recording from the enclosure?

zoundsabar · 2024-04-10T08:49:02.717Z

I haven’t made any sort of scientific comparison between with and without the furries, but I’ve also not noticed any detrimental difference between them. I figure that the AudioMoth has an emphasis towards the upper frequencies and some attenuation there won’t be very noticeable.

It’s always good to have wind protection available for when you need it!

fellowfinch · 2024-04-11T19:42:11.471Z

zoundsabar:

It’s always good to have wind protection available for when you need it!

which in my part of the woods is almost everytime

EDIT:

recovered my audioMoth from it’s first deployment in the dense wooded are of our main park in Ljubljana. Really wanted to see what activity I might capture in the night time, but after going through the recorded material I mostly found just occasional branch interruption, probably by some passing by animal or random falling debris and distant traffic like motors, cars and trains.

I’ve had it set to 48khz, but managed to pick up some bat echolocation near the top range of of 20khz and as low as 9khz. This led me down to research a bit and I soon found out that it is most likely a Nathusius Pipistrelle, which can be found foraging in the dense wooded area - I’ve compared these to the recordings I made outside my apartment window with Echo Touch 2 and found out that we do have a higher activity of Kuhl’s and Soprano Pippistrelles, characterised by more monotone calls in higher ranges. So, at least an interesting sidequest from rather uneventful 3 nights of recording.

I do want to ask for those owners of audioMoth, does your unit have quite a lot of self noise or rather bad signal to noise ratio?

and what would be a good configuration for quieter evenings?

Glamaig · 2024-04-24T13:30:47.731Z

Love this thread, have so been enjoying the conversation. I am doing a MSc Music and the Environment so I thought I would try to include these ideas within music composition, not that easy. I built a system of band splitting a sound walk recording, into envelope followers and gate extractors, then using the gate/cvs to move through various sets of quantised voltage to create the melodic elements and progression more generally. I built a 16-voice resonator to process the recording and printed the whole thing to a prepared tape loop as I do all the time (need to hear those crinkles :). Anyway, maybe it’s rubbish but posted here in case of any interest, cheers!

fellowfinch · 2024-04-24T14:33:17.515Z

woah, is this Skye in Scotland? It’s probably the most magical place I’ve ever visited.

Glamaig · 2024-04-24T14:36:55.870Z

Hi there, yeah this is where I live, lucky chap. The rudimentary video here is from an area only a short drive away…glad you loved it

Catchthehare · 2024-04-24T14:45:53.421Z

I stayed 2 nights and 3 days in Skye, what an amazing place. Dynamic is the best adjective I can think of to describe the weather.

Glamaig · 2024-04-24T15:26:25.268Z

I agree…all weathers, all day, every

filippoferreira · 2024-04-25T21:48:44.406Z

Curious to know what techniques, tools, and/or concepts you all use to emulate acoustic spaces in your music productions. I am particularly interested in eco acoustics and how to re-create them with electronic instruments and effects.

Glamaig · 2024-04-26T11:06:47.572Z

Personally it’s convolution all day long

filippoferreira · 2024-04-26T15:44:17.023Z

Same here! And field recordings through resonators. Would love some other ideas and techniques though!

Glamaig · 2024-04-26T17:03:42.792Z

Have you tried field recordings as modulators (FM/AM/PWM/FOLD? Also spectral transfer? Fumana, Bark filter kind of thing, can work really well? Another one I like is take a VCO or sound source, turn the pitch down, add noise to the FM and a field recording to 1/v, can get really interesting noise oscillator stuff there. Can also work great if you get like a filter with a bit of W and do the same to it’s frequency cutoff….