Acoustics / Feed

Acoustic monitoring is one of our biggest and most active groups, with members collecting, analysing, and interpreting acoustic data from across species, ecosystems, and applications, from animal vocalizations to sounds from our natural and built environment


Thoughts on new MSc in Conservation Technology

Hello everyone, We are in the process of developing a new MSc in Conservation Technology at my university and would welcome your feedback. If you would be willing to give...

1 1

Hi @emmahiggins

sounds like a great plan. 

Could you tell more about the content of the program, and perhaps the institutional context (which department(s) is(are) going to offer the course, and which research programs or projects are related to it) , so we'll have something to orient our thoughts?

See full post

Mounting Electret Microphone

Hi all,I'm curious to hear experiences/thoughts on mounting microphones in potted instrument housings that will receive a fair amount of movement and vibration. This is for an...

1 0

If you search Digikey for a 'strain relief' you should be able to find a rubber grommet that will hold that mic without any additional machining. A blob of silicone will adhesive and  waterproof, I always like stuff to do at least two things. It's also vibration reducing on the mic. You may want to either 'shotgun' mic by putting it at the end of a tube, that will block a lot of ambient also. Unless it whistles like a bottle in the wind, that might be a problem later lol. Or use a dish as a focus. 

See full post

Uploading External Recordings for Templates?

Hi All!I'm still pretty new to Arbimon so I'm hoping to get some help from some more experienced folks.I'm researching avian and bat biodiversity impacts (among other things) of...

2 0

Hi Cortney! 

I'm Carly, the Science Outreach Lead at Arbimon :) 

I wanted to just point out that we have support docs and help pages at and also a link to contact us directly for help! 

Regarding the error you're getting with the upload, it's probably easiest to switch over to email so I can get more information on the project and look into it on the backend. I would also recommend using the Uploader App rather than the web uploader, if you're not already. 

But your idea is correct, we have many users who import renamed Xeno-Canto files to Arbimon to use as templates! 

What's your email? We can continue the convo to get you set up!

See full post

Audiomoth Energy consuption estimates

Hi All,I'm conducting a biodiversity survey that includes a grid of audiomoths. I have 53 deployed, with the following schedule: 15 seconds every minute, 4:00-12:00, and 16:00-24:...

15 0

We had this same issue, and found that the firmware version 1.9.2 was our issue. We bumped it back to 1.9.0 and our energy consumption was back to normal. 

We record data for 7 hours a day (3.5 hour blocks), using sandisk extreme 64GB micro SD cards. We don’t use re-chargeable batteries, and the ARUs are set for 14-day periods before being collected. With the 1.9.2 firmware, for some reason they’d only record for maybe 9 days tops before dying. At firmware 1.9.0, we were back to our normal recording of minimum 14 days (although they often last longer). We tried different batteries, different energy saving settings, nothing worked besides bumping the firmware down. This issue was in both our brand new AudioMoths and 2-year old AudioMoths. 

I hope this helps. 

Hi Tabitha, What recording settings were you using when you saw these differences? I've measured the consumption across some different firmware versions and I can't see any difference. Were these AudioMoth 1.2.0 devices? Alex

See full post

WILDLABS AWARDS 2024 - Developing AudioMoth for the detection of infrasonic elephant rumbles

As recipients of the WILDLABS AWARDS 2024, our team - formed of Open Acoustic Devices (@Andrew_Hill, @alex_rogers, @PetePrince ) and the Zoological Society...

12 12

Hi Alex,

Very cool, that would give us lots of room for collaboration since we are focussing on model development taking hardware restrictions and inference speed into account.

Wow.. Really exciting to see this effort. Congratulations on the award!

I have been interested in this subject for a long time, as we have elephant-human conflicts in plenty in India (my country). Sometime back I had hacked a computer optical mouse as a seismic detector in order to study elephant intrusion into farmlands (where they are considered as pests). But I think we need more robust detectors. I am also considering laser led self-mixing as a technique to get a good alternative to expensive geophones. Wish you all the very best.

Wow.. Really exciting to see this effort. Congratulations on the award!

I have been interested in this subject for a long time, as we have elephant-human conflicts in plenty in India (my country). Sometime back I had hacked a computer optical mouse as a seismic detector in order to study elephant intrusion into farmlands (where they are considered as pests). But I think we need more robust detectors. I am also considering laser led self-mixing as a technique to get a good alternative to expensive geophones. Wish you all the very best.

See full post

Advice on a Master's project

Hi all, I’m posting here to ask for a some advice. Sorry in advance for the long post. I’m currently studying for an integrated masters in Electrical and...

24 0

Yes. The key output for synchronisation is the pulse per second (PPS) output which is synchronised very accurately to UTC. The TX from the GPS module is then useful for reading the time and positions. You generally don't need to be able to send commands to the module as most of the time the default settings are fine.

Hi Harry (and all)

Just wanted to share some potentially relevant papers that I've come across, in case you haven't found them already. Coming more from the ecology/conservation focused side of conservation tech, but potentially of use to see what's actually been deployed out there! 

Yip, D. A., Knight, E. C., Haave‐Audet, E., Wilson, S. J., Charchuk, C., Scott, C. D., ... & Bayne, E. M. (2020). Sound level measurements from audio recordings provide objective distance estimates for distance sampling wildlife populations. Remote Sensing in Ecology and Conservation, 6(3), 301-315.

Abadi, S. H., Wacker, D. W., Newton, J. G., & Flett, D. (2019). Acoustic localization of crows in pre-roost aggregations. The Journal of the Acoustical Society of America, 146(6), 4664-4671.

Spillmann, B., van Noordwijk, M. A., Willems, E. P., Mitra Setia, T., Wipfli, U., & van Schaik, C. P. (2015). Validation of an acoustic location system to monitor Bornean orangutan (Pongo pygmaeus wurmbii) long calls. American Journal of Primatology, 77(7), 767-776.

Kershenbaum, A., Owens, J. L., & Waller, S. (2019). Tracking cryptic animals using acoustic multilateration: A system for long-range wolf detection. The Journal of the Acoustical Society of America, 145(3), 1619-1628.

Stinco, P., Tesei, A., Dreo, R., & Micheli, M. (2021). Detection of envelope modulation and direction of arrival estimation of multiple noise sources with an acoustic vector sensor. The Journal of the Acoustical Society of America, 149(3), 1596-1608. 

Rhinehart, T. A., Chronister, L. M., Devlin, T., & Kitzes, J. (2020). Acoustic localization of terrestrial wildlife: Current practices and future opportunities. Ecology and Evolution, 10(13), 6794-6818.


Long time, no update. @StephODonnell suggested I post here with my thesis and some reflections.  



My thesis looked into the effects of environmental parameters like wind, temperature, and vegetation on acoustic classification and localisation of terrestrial wildlife, aiming to shed light on the implications for study design.



My thesis centred on improving acoustic data acquisition via an analysis of the physics of sound propagation. The idea driving this was that there isn't enough attention paid to environmental effects on sound. The hope was that this could be used to improve the design of acoustic monitoring systems. COVID shifted the direction away from any practical work, but thankfully we managed to find our way through it by using data within the literature. 

The thesis is split into two main sections:

  • Improving SNR for sound classification

I explored environmental factors affecting SNR and their implications for the detection space of a signal. 

I've briefly had a look through updates in the field since my thesis, and there is a great paper here. This paper takes a similar approach but does so far more elegantly and completely - definitely worth exploring!

  • Error Analysis in Sound Localisation

I explored how differing environmental conditions from those assumed can influence the TDOA error on a microphone pair, and thus position error. The main parameters looked at were temperature, humidity, wind speed & direction and 2D model error.


I ended with some recommendations for system design such as adding additional sensors for more intelligent monitoring systems, or how to maximise the study area by maximising your SNR.  

I also discussed future work. The dream output would have been taking the analysis in the thesis and creating an online tool to be used to optimise sensor placement. Practitioners could use it to quickly input their study features to determine the likely important parameters for their deployment location, and how they can improve data quality. This would involve taking the analysis in the thesis and packaging it into an app - I'm thinking R Shiny or similar.



In the end, I felt that it took a long time to figure out a direction for the project , and how to actively contribute to the space. It was (obviously) difficult as I didn't come into this with prior knowledge or a structured plan, and so I was a little disappointed with the outcome. It would have been great to explore some of the things I put down as "future work" - but I guess that's part of the process.

The project was a great intersection of technology and environment and it definitely helped shape the next few years for me. Since finishing I have taken a couple of detours into the workforce. First to a marine robotics company, and then measuring forest carbon with LiDAR. I've now just started a PhD using ocean modelling to map biodiversity in the ocean with an AUV.  So despite the challenges in trying to design a project within my interests, it has been pretty foundational for me going forward!

Thanks to everyone that offered help and advice. Likewise, I'm very happy to answer any questions from other students/anyone, and  I'm really looking forward to being back in the wildlife tech space!


Thesis available here.

See full post

Affordable acoustic monitors for "whispering" bats?

Hi everyone,New here and new to bat acoustic monitoring. I'll be conducting a study where I'd like to acoustically monitor bats, including "whispering" (relatively quiet) bats...

6 1
See full post

Acoustically Transparent Epoxy

Hello all,I'm developing an animal-borne passive acoustic monitoring system and plan to pot the internal electronics in the housing with epoxy to waterproof the system. We're...

6 1

Same issues here. A MEMS is a great idea to pot, but you really need a piezoelectric element for this to work and not a MEMS based on capacitance (btw they're all capacitance, except for one now discontinued...). It was originally made by Vesper, but the company was bought out last year and the MEMS is no longer made. 

This is because you're no longer really doing a typical microphone, this would be a contact type hydrophone. For waterproofing, you can actually get a waterproof MEMS. As long as your not submerging this for an extended period, it should do the job. Be sure to keep the cable short between the PCB and the mic as you'll get noise as I've experienced. 

For generally answering your question on the "best" epoxy to with sound transparency, in general the harder the material the lower the acoustic impedance. I use Epotec 301 resin with a hardness of 85. Your shape will also influence the resonance frequencies, meaning the flat frequency response will now be distorted and you'll probably have distorted audio. . 

You generally don't want to pot MEMS microphones since they're designed to pick up on air pressure changes and adding any material in front of the microphone just introduces another transition layer where pressure waves need to propagate through. Also, potting the MEMS microphone can be tricky since if you get any material in the port, you could damage the microphone or drastically reduce its performance. If you want to seal something with epoxy, take a look at contact microphones. Higher frequencies will be attenuated but depending on the application, it could work. 

There are companies, however, that design fabrics that are waterproof/resistant but have a relatively low acoustic impedance. SAATI has a variety of samples that you can request and GORE makes Acoustic Vents that could work. You can design a mechanical housing around your MEMS microphone with small perforations that are covered by one of these materials. I did this for one of my latest projects and it holds up just fine in heavy rain conditions. 

Hi Jesse,

For a material to be acoustically transparent (in air), the speed of sound in the material times its density must match that of air.  Realistically, any solid material will have a greater density than air, and a higher speed of sound to boot, so I'm afraid there's no way to match it to air.  Sorry.

See full post

CollarID: multimodal wearable sensor system for wild and domesticated dogs

Hi Everyone! I (and my team) are new to the WildLabs network so we'd like to post an early-stage project we've been working on to get some feedback!  SummaryThe...

2 5

Hi Patrick, 

This is so cool, thanks for sharing! It's also a perfect example of what we were hoping to capture in the R&D section of the inventory - I've created a new entry for #CollarID so it's discoverable and so we can track how it evolves across any mentions in different posts/discussions that come up on WILDLABS. This thread appears on the listing, and I'll make you three the contacts for it too. But please do go in and update any of the info there as well! 


See full post

Drop-deployed HydroMoth

Hi all, I'm looking to deploy a HydroMoth, on a drop-deployed frame, from a stationary USV, alongside a suite of marine chemical sensors, to add biodiversity collection to our...

4 1

Hi Matthew,

Thanks for your advice, this is really helpful!

I'm planning to use it in a seagrass meadow survey for a series of ~20 drops/sites to around 30 m, recording for around 10 minutes each time, in Cornwall, UK.

At this stage I reckon we won't exceed 30 m, but based on your advice, I think this sounds like not the best setup for the surveys we want to try.

We will try the Aquarian H1a, attached to the Zoom H1e unit, through a PVC case. This is what Aquarian recommended to me when I contacted them too.

Thanks for the advice, to be honest the software component is what I was most interested in when it came to the AudioMoth- is there any other open source software you would recommend for this?

Best wishes,


Hey Sol, 

No problem at all. Depending on your configuration, the Audiomoth software would have to work on a PCB with an ESP32 chip which is the unit on the audiomoth/hydromoth, so you would have to make a PCB centered around this chip. You could mimic the functionality of the audiomoth software on another chip, like on a raspberry pi with python's pyaudio library for example. The problem you would have is that the H1A requires phantom power, so it's not plug and play. I'm not too aware with the H1e, but maybe you can control the microphone through the recorder that is programmable through activations by the RPi (not that this is the most efficient MCU for this application, but it is user friendly). A simpler solution might be to just record continuously and play a sound or take notes of when your 10 min deployment starts. I think it should last you >6 hours with a set of lithium energizer batteries. You may want to think about putting a penetrator on the PVC housing for a push button or switch to start when you deploy. They make a few waterproof options. 

Just somethign else that occured to me, but if you're dropping these systems, you'll want to ensure that the system isn't wobbling in the seagrass as that will probably be all you will hear on the recordings, especially if you plan to deploy shallower. For my studies in Curacao, we aim to be 5lbs negative, but this all depends on your current and surface action. You might also want to think about the time of day you're recording biodiversity in general. I may suggest recording the site for a bit (a couple days or a week) prior to your study to see what you should account for (e.g. tide flow/current/anthropogenic disturbance) and determine diel patterning of vocalizations you are aiming to collect if subsampling at 10 minutes. 



Hi Sol,

If the maximum depth is 30m, it would be worth experimenting with HydroMoth in this application especially if the deployment time is short. As Matt says, the air-filed case means it is not possible to accurately calibrate the signal strength due to the directionality of the response. For some applications, this doesn't matter. For others, it may.

Another option for longer/deeper deployments would be an Aquarian H2D hydrophone which will plug directly into AudioMoth Dev or AudioMoth 1.2 (with the 3.5mm jack added). You can then use any appropriately sized battery pack.

If you also connect a magnetic switch, as per the GPS board, you can stop and start recording from outside the housing with the standard firmware.


See full post

Your HydroMoth experience!

Hi everyone,we just got our first dedicated #hydromoth in the post box. Anyone else about to start their bioacoustic journey? I would love to share our experiences, settings and...

7 1

Vinegar is also a great solution! Let it sit overnight and then just scrub it off. As a warning if you don't clean it, your sensitivity does decrease. You might actually see this if you keep it out there for a month that the amplitude of your calls decrease over the month/you might detect fewer calls. 

Hey! I would recommend a few things:

1) set up at least two in the same site kind of back to back or side to side if you have that many. Directionality can influence the number of calls you get and it's just good to know your error rate. 

2) Experiment with breaks and recording duration. You wont collect anything if the write time is not long enough to record to your SD card and you'll get empty files. 

3) Clean your device every time you take it out or see visible biofouling. Also, add silicon grease every time to your O-ring. Take it out with an O-ring pick and clean the plastic seal, looking for any type of sand/mud/debris. We've had a few flooding incidences, but this is probably because we open them all the time.  

4) lower the frequency rate the more data you can collect, so keep it as low as your frequency of interest without clipping your calls. Fish are lower than pretty much everything (2kHz-3kHz). 

I hope this helps! 

See full post

Hydromoth settings

Hi Everyone,what is your #HydroMoth setup for freshwater ecoacoustic monitoring? What are your settings for underwater recording with your AudioMoth? I would love to dicuss...

8 0

Hi Ian,

I have hours of an unidentified creature recorded during overnight recording sessions with mutliple hydrophones. We think it is platypus but there is nothing to compare against that isn't from captive sounds. I am waiting on the Hydromoth to become available again so I can do longer term monitoring.

Hi everyone, I just got my first hydromoth and wanted to test it for aquatic soundscape with interest in Tomistoma, Otter, boat traffic and maybe fishes too!  But before that I maybe test it on zoos.

What are your advices, tips, or suggestion for first-time user? thank you!

You won't get any audio if you don't allow enough time for the hydromoth/audiomoth to write. So when you do a continuous recording you need to experiment a little. I'm sure there is a formula to calculate this, but I haven't figure that out. I typically do 5 min recordings with 10 seconds of write/break time. I think this system is expecting you to subsample, so keep that in mind instead of a continuous recording. 

I do 8kHz sampling and get about 7 days of data and then the voltage gets too low and you start getting SD card write errors and missing files. 

In terms of analysis, I've had trouble understanding the directionality of the hydromoth and incorporating this into my studies. I always set up two at the same site to check the variability in my call detections and include this into my error analysis. 

See full post

WILDLABS AWARDS 2024 - Underwater Passive Acoustic Monitoring (UPAM) for threatened Andean water frogs

In our project awarded with the "2024 WILDLABS Awards", we will develop the first Underwater Passive Acoustic Monitoring (UPAM) program to assess the conservation status and for...

5 15

This is so cool @Mauricio_Akmentins - congrats and look forward to seeing your project evolve!

Congratulations! My first hydromoth was just arrived yesterday and so excited! Looking forward for the update from your project!!!

See full post

Introducing The Inventory!

The Inventory is your one-stop shop for conservation technology tools, organisations, and R&D projects. Start contributing to it now!

5 14
This is fantastic, congrats to the WildLabs team! Look forward to diving in.
Hi @JakeBurton,thanks for your great work on the Inventory!Would it be possible to see or filter new entries or reviews?Greetings from Austrian forest,Robin 
See full post

Attaching a directional microphone to a Wildlife Acoustics ultrasonic recorder?

Background: I am still new to acoustics research and I am hoping to get some advice on integrating a directional microphone with an ultrasonic recorder....

3 0

Hi Luke, sounds like an interesting project! One thing to note is the ultrasonic Wildlife Acoustics unit you're looking at is already fairly directional. Take a look at the horizontal directionality plot towards the bottom:

You can see that for the relevant frequencies for slow lorises ultrasonic calls (40-60 kHz), there is 25-30 dB difference between 0 and 180 horizontal degrees. It's not perfect, but is close to some directional mics, and if it works well enough for your project it would save a lot of time and testing!

If you do choose to integrate an external directional microphone, be careful with microphone placement to avoid potential ultrasonic reflections from any hard flat surface like a tree trunk, water surface, or the instrument housing itself. Here's an example of some echo calls from reflective surfaces from bat vocalizations: 

It would be helpful to hear how you plan on obtaining behavioral information (and what kind) to correlate with vocalizations? Observations, cameras, biologgers, etc.? This could inform responses a bit more.

Hi Jesse,

Thank you so much for your reply and for the fantastic knowledge and resources! I was unfamiliar with the plots, so thank you for providing some interpretation- I will have to work to better understanding them. This may change things (I was going off of experience from field work with the last iteration of this WA recorder which had omnidirectional recording) and I may choose to pilot the recorder without an external microphone this summer. 

Regarding my plan for collecting behavioral data, I plan to follow 15 wild individuals in a reserve in Thailand (mostly dry evergreen and dry dipterocarp forest with some human modified areas). I intend to use instantaneous focal sampling to observe lorises in two shifts between 18:00-06:00h. During these focal follows I will record all behaviors at 5-min intervals and use all-occurrences sampling for social and feeding behaviors, using an established slow loris ethogram. Simultaneously, I plan to record vocalizations, with the help of a research assistant and field guide. So we will be carrying the recorder with us during behavioral data collection. I intend to match up the timestamped loris vocalizations with the behavioral data to understand the call's function.

If you have the resources, I would suggest testing the sensitivity and directionality of the system at relevant frequencies both with and without an external mic, and let the results dictate which will be best for your case study.

Another thing to think about since you are manually taking the recordings is if a WA unit is really necessary. You're paying for the technology of a remote system without needing it. Other cheaper handheld recorders (such as Zoom recorders) could free up $$ for a higher quality directional microphone. Although of note is that common Zoom recorders like the H4n only sample up to 96kHz for which the upper frequency limit (48kHz) is getting very close to the frequencies you're likely wanting to measure.

See full post

WILDLABS AWARDS 2024 - Fostering bat conservation and citizen science in Zimbabwe: Establishing bat groups and training individuals to use bat detectors

Through our project, awarded by the WILDLABS Awards 2024, we aim to establish three bat groups across Zimbabwe. These groups will be trained to use Echo Meter Touch 2 Pro bat...

4 11
See full post

Thoughts on RooBadge?

I came across this new Volkswagen initiative today, RooBadge, a vehicular kangaroo deterrent that uses telemetry data to automatically play high-frequency sounds in dense kangaroo...

5 3

Sound deterrents to prevent collisions with Kangaroos in Australia have been sold for many years. None have been shown to work. Whether the Volkswagen device will be any better waits to be seen. Collision data will have to be collected for a while to see if the VW device has any effect on collision rate.

That is an interesting concept, and it would be great if something out there worked. In the meantime, I will try not to drive at dusk 🦘

At one point, I knew the "sonic" animal guards were the most stolen components of cars. You head in, get groceries, and come out, and they are gone. They weren't on the car long enough for me to confirm that would work

See full post

WILDLABS AWARDS 2024 - BumbleBuzz: automatic recognition of bumblebee species and behaviour from their buzzing sounds 

The 'BumbleBuzz' team (@JeremyFroidevaux, @DarrylCox, @RichardComont, @TBFBumblebee, @KJPark, @yvesbas, @ilyassmoummad, @nicofarr) is very pleased to have been awarded the...

2 5

Super great to see that there will be more work on insect ecoacoustics! So prevalent in practically every soundscape, but so often over-looked. Can't wait to follow this project as it develops!

See full post

WILDLABS AWARDS 2024 - TimeLord: A low-cost, low-power and low-difficulty timer board to control battery-powered devices

Hi everyone,@Alasdair from Arribada Initiative and I are so pleased to announce our TimeLord project as one of the lucky winners of this year's WILDLABS Awards. What is TimeLord...

14 14

Thanks @Freaklabs, I think you'll really enjoy getting involved with this too as we're looking for input from makers in the community to get the most from the approach and to capture features and usability ideas from a large number of people.

I've a new modular drop-off tag build using @Rob_Appleby's original SensorDrop board that I think would be great for this project too to see if we can drop different compartments, or do various different timed events with the one TimeLord board.

Most importantly, we have to make it play a MIDI version of the DoctorWho theme song when you arm the device. That has to be the #1 feature if you ask me!


See full post

WILDLABS AWARDS 2024 - FinDrop: Accessible Acoustic Monitoring for Mesophotic Marine Environments

Hello everyone! I am honored to introduce our interdisciplinary team, which has experienced exponential growth over the past year, comprising individuals such as @...

1 2

Congrats @MattyD797 and team!!! We do a lot of work in the underwater bioacoustic realm and your tool certainly seems like it would be a great instrumental addition to the community. Look forward to learning more about your project!


See full post