Conservation Bioacoustics: Listening to the Heartbeat of the Earth

Recent advances in technology have allowed scientists to gather larger quantities of acoustic data from locations more remote than ever before. As a result, the study of animal sounds can be used to inform species or habitat conservation and natural resource management practices in new and exciting ways. In this episode, we talk to Aaron Rice of Cornell University about how acoustics can be used to advance conservation efforts, as well as how folks outside of large research universities can take part in efforts to help save the planet with science.

Read the associated article: Aaron N. Rice, Marissa L. Garcia, Laurel B. Symes, and Holger Klinck. (2023) “Conservation Bioacoustics: Listening to the Heartbeat of the Earth,” Acoustics Today 19(3). https://doi.org/10.1121/AT.2023.19.3.46

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Intro/Outro Music Credit: Min 2019 by minwbu from Pixabay. 

Transcript

Kat Setzer  00:06

Welcome to Across Acoustics, the official podcast of the Acoustical Society of America's publications office. On this podcast, we will highlight research from our four publications. I'm your host, Kat Setzer, editorial associate for the ASA.

Kat Setzer  00:24

Today, I'm talking to Aaron Rice about his article, "Conservation Bioacoustics: Listening to the Heartbeat of the Earth," which appeared in the fall 2023 issue of Acoustics Today. Thanks for taking the time to speak with me today, Aaron. How are you? 

Aaron Rice  00:36

I'm doing great. Thanks for having me. 

Kat Setzer  00:37

Yeah, you're welcome. So first, just tell us a bit about your research background. 

Aaron Rice  00:41

So I grew up with a love for the ocean and a fascination for fish. And I knew early on that I very much wanted to really get into marine biology as a discipline. And it wasn't until I started looking at graduate school that I actually become aware of this field of bioacoustics and started talking with a prospective advisor, and he brought up the idea, it's great you like fish, you're interested behavior and ecology. Have you ever thought about fish acoustic communication? And at that point, being a precocious child thinking I knew a lot of things about a lot of things, but very quickly realized I'd never heard of the idea of fish making sounds. I said, "What? I never heard of this before." And it was sort of that formative conversation sort of made me aware of this field of bioacoustics and the study of animal sounds. And one thing led to another and many, many years later, here I am. 

Aaron Rice  01:35

And so it's, I think, what's exciting, or what captivated me about bioacoustics, particularly underwater, is there are so many discoveries to be made. Yes, where we stand now sits on decades of research, but there are constantly new things that we're learning and new applications. And I've always enjoyed fiddling with technology and using new tech approaches. And so the field of bioacoustics very much captured my interest of trying to understand how organisms do what they do in cool places like underwater, and then being able to bring about or bring into it different hardware and software approaches to try to understand those questions. 

Kat Setzer  02:12

Yeah, and we'll get into probably more of the technological changes later. But it does really sound like because of the advent of the digital era with, you know, all we can do with computers now, it's really set the stage for a lot of conservation bioacoustics efforts. But to get started, what is conservation bioacoustics? And how did this concept come about? 

Aaron Rice  02:33

So the idea of conservation bioacoustics I think has actually been around for a while. But the first time you start seeing the combination of those two words in the scientific literature, there's a paper on insects in the late 90s, but then there was a review paper in Biological Conservation in 2010 that really talked about bioacoustics and conservation. And the idea is how can you use the study of animal sounds to inform species or habitat conservation and natural resource management practices? So I think that for many of us that are practitioners of bioacoustics approaches, it's a fairly implicit connection between bioacoustics methodologies and the desire for conservation outcomes. 

Aaron Rice  03:21

And I think probably the best example of this is that many of the approaches or motivations for using bioacoustics was initially applied to endangered species, whether that's birds, or whether that's cetaceans. And so because of that emphasis on trying to understand cryptic yet endangered species, there is early on, in the field that we now know as passive acoustic monitoring, very much has a conservation connection. And so, you know, when we think about the different areas of conservation, some of it's resolving data gaps, some of it's trying to assess animal risks from anthropogenic factors. It's trying to understand range shifts, and trying to understand changes in behavior over time. All of these are things that we can do through the field of bioacoustics and passive acoustic monitoring. 

Aaron Rice  04:11

And so what we wanted to be able to define in this particular paper was taking what has been an assumption for so long by so many practitioners in bioacoustics of the connection between this and conservation, and translate that implicit connection to something much more explicit and clearly articulated. So we can think about with bioacoustics as both a suite of questions as well as a suite of tools. How can we really target urgent conservation needs and questions through this arena of bioacoustics? 

Kat Setzer  04:46

Okay, okay. So you kind of touched on this a little bit, but generally speaking, how can acoustics data be used in conservation efforts, and what is the benefit of using acoustic data as opposed to any other data when you're studying an ecosystem? 

Aaron Rice  05:04

So for a lot of the species that we study, whether they're elephants in the forest of central and western Africa, whether they're whales underwater, whether they're frogs calling at night, or birds up in the trees, what many of these imperiled species have in common is they're really tough to see, they tend to be loud, they tend to be really easy to detect through sound. And what really constrains a lot of conservation efforts now for cryptic species is there are fundamental data gaps that remain. We don't know aspects of their life history, their ontogeny, particular critical periods of time of reproduction, or feeding or territoriality. We don't know in many cases where they're distributed or particular patterns of space use and how that changes throughout seasons. And all of those are questions that we can address through bioacoustics. 

Aaron Rice  05:52

The other component, too, is trying to understand within a conservation framework, what are the risks from human activities that imperiled species are subjected to, and so, perhaps not surprisingly, something like anthropogenic noise is really great to be able to measure through bi0acoustics approaches. And so being able to look at both chronic and acute noise exposure to organisms, the prevalence of different types of anthropogenic noise in different habitats-- these are all things that are naturally aligned with bioacoustics. 

Aaron Rice  06:25

The other really valuable thing with bioacoustics or passive acoustic monitoring is that it provides a extremely rich and pervasive record of data collection over time. So if you think about many more traditional conservation efforts that are relying on visual surveys, if you're lucky, maybe you go to a field site once a day, once a week, once a month, to look for your favorite critter. Whereas if you have autonomous recording devices that are deployed out in the field, they're recording constantly. And so what develops is this continuous record of the soundscape-- not only what the species is doing, and how we can interpret that through its acoustic behavior, but also changes in the soundscape, whether those are anthropogenic sounds, or environmental sounds such as weather. 

Aaron Rice  07:15

What's particularly valuable about acoustic data is again, I've used this word pervasive. So because it is this complete record of everything in the soundscape that the recorder can detect. What we can do is, let's say, we deploy recordings for an acoustic survey for one particular species of interest. Well, years later, we can ask the question, "Oh, hey, we now have this other species that we're really interested in. Are there any previous efforts to target that species?" and lo and behold, we can go back to the filing cabinet, or, go back to a cloud server, and reutilize a lot of this archival acoustic data to analyze again and again and again, the data for different particular species. So we can have a frog survey going after an endangered frog, and then, years later, somebody could say, "Oh, but what about the insects that we're interested in? Do they occur too?" And sure enough, we can go back and analyze data from that frog survey specifically for insects. And we've done this for different species of whales; we've done this for a different species of fish that had been picked up on whale recordings. 

Aaron Rice  08:21

And the other component, too, is that because these are pervasive records, we can start to assemble very large datasets covering ocean basins or entire continents through individual survey efforts, and have a really long-duration, broadly distributed spatial scale set of recordings that allows us to take bio coustics into what we're now thinking of as the big data domain, where we have massive amounts of data that we can use for addressing sort of fairly large-scale conservation questions. 

Kat Setzer  08:56

Okay, yeah, that makes a lot of sense. But how do you take all of that data, like if you've got a huge data set, how do you take that and create policy based on it?

Aaron Rice  09:04

So one of the probably the most immediate things that have been done is trying to understand where and when species occur. So within the US Federal statutes for particular endangered species, such as North Atlantic right whales, one of the big conservation measures is being able to establish critical habitats. And so we did a few papers through fairly baseline passive acoustic surveys demonstrating that North Atlantic right whales were occurring in different areas, either in the Northeast or down in the Southeast in their calving grounds for much longer throughout the year than visual surveys had previously identified, and what that led to was an expansion of the critical habitat and protected areas that right whales reside in, as well as enhanced seasonal measures for seasonal management areas, recognizing that their occurrence in particular areas was not limited to a few weeks or maybe a month, throughout the year; it was much, much longer than that. And so it's being able to take these basic data gaps, provide an updated understanding of animal occurrence, and fold that into different protective measures for things like habitats or population status. 

Aaron Rice  10:20

Another example of a project that we have done is being able to identify different species through the sounds that they produce. And so what started out as a passive acoustic survey following the Deepwater Horizon oil spill in the Gulf of Mexico, working with the regulators, they said, "Hey, we want you to listen for Bryde's whales in the Gulf, because we're concerned about how the oil spill may have impacted them." And so we initially asked the question, "Sure, we could do that. What do they sound like?" And the feds came back and said, "Well, we're not sure." Okay, this will be interesting. And so, trying to take corroborating data with what's the general frequency range of a baleen whale species, being able to deploy localization arrays to figure out where and when are these sounds distributed, how quickly are they moving. And a paper that we published in The Journal of the Acoustical Society of America about a decade ago now, sort of addresses this idea of saying, if we don't know what the species is, but if it sounds like a whale, and it swims like a whale, and it's distributed in the general area where these whales are supposed to occur, there's pretty good corroborating evidence that these are the sounds in fact of Bryde's whales. 

Aaron Rice  11:31

Well, fast forward through the efforts of the National Oceanic and Atmospheric Administration. Our behavioral data ended up being corroborated by folks at Scripps as well as NOAA southeast Fisheries Science Center, and then was combined with genetic data to first identify that the Gulf of Mexico Bryde's whale population was in fact genetically distinct from other Bryde's whale populations around the world, which then through the genetics work led to that particular species being listed as endangered under the US Endangered Species Act. And then further genetic work identified, in fact, the Bryde's whales in the Gulf of Mexico were their own distinct species, which is now recognized as the Rice's whale. And so what's helpful is being able to have some of this initial evidence of behavior through sound, have those data streams be combined with more traditional sort of population assessment methodologies such as genomics, which can then lead to the designation of either endangered species or identification of new species. And so it's not to say that we led to the discovery of this as a new species, but the bioacoustics provided really compelling corroborating evidence to then further expand the scope of this fundamental genetics work. 

Kat Setzer  12:49

Okay, got it. Got it. It sounded like a whale, but it wasn't quite the same sounds as the whales that you've heard before. Okay, so let's talk more about the recording. Obviously, conservation bioacoustics is pretty dependent on recording sounds in a given environment. How has that changed over the years?

Aaron Rice  13:13

So a lot of it is been limited to the types of questions at a given instant are constrained by the available technology. And if you think back 15 years, where we had cassette tapes, or reel-to-reel tapes, you could record for maybe an hour, an hour and a half, if you're lucky. And as an investigator, you could listen to your entire recording. And what people would do is they would sit down, put on their headphones, listen to the recording, and maybe have a checklist of species that they heard or annotate over time when particular sounds were heard. In the analog days, what we now know as spectrograms, were initially created from the waveforma of the oscillogram by something called the K-sonograph, which is why you hear some of the initial terminology or synonyms of spectrograms as being referred to as sonographs. And so it was the idea of being able to take different visualizations of the sounds and look at it both in the spectral domain as well as the temporal domain. But, early on we're dealing with short-term data here, maybe it's minutes, maybe it's an hour if you're lucky. With the advent of digital recording technologies, and being able to step away from things like tape, we can now take those recordings, not in dealing with hours, but we could be dealing with days, months, or even years in cases. And so whereas a particular data set, 20 years ago would be amazing if you had 10 hours of recording, we now generate in some of our passive acoustic surveys, more data than one can listen to in a single career span or a lifetime.

Aaron Rice  14:50

And so being able to conduct a multisensor passive acoustic survey, whether it's underwater or in a terrestrial ecosystem, very frequently, you're producing 10 to 50 years of audio data in the scope of that project. And so, you there's been this just completely exponential increase in the amount of data that can be collected. The challenge is, if we were first able to go through and listen to the data, because we had time to do that, there's a variety of different analytical approaches that you could utilize to mark up or to analyze the data set. Now, with having extensive amounts of data, where it is physically impossible to listen to all of it, what that has then pushed is advances in the signal processing and the software domain, where not only through visualization, but being able to take what used to be referred to as automated detection approaches, and has now been sort of incorporated with the artificial intelligence and deep learning domains of training computers to recognize sounds for you, and being able to go through and have the computer do an extensive amount of the annotation and analysis of the sound recordings that humans used to be sort of constrained in doing themselves. 

Kat Setzer  16:11

Okay. Yeah. So it sounds like you went from having a dearth of data to almost more than you can manage, or--

Aaron Rice  16:17

Oh, absolutely, 

Kat Setzer  16:18

that we're dependent on AI to help us manage. So as we're discussing, the transition to digital recording, has had a big impact on the field, since it's made it so much easier to get and analyze data. What are some of the major advances that have impacted the field? 

Aaron Rice  16:33

Yeah, so certainly, AI is completely transforming the way we're doing things, and being able to take validated training data, where we're telling the computer, "Okay, this is what this species sounds like," being able to capture some degree of variability, and then evaluating the performance of that algorithm and then unleashing it on a massive scale has allowed us the ability to analyze these datasets in pretty short amounts of time. So we can be able to process, in some cases, years of recordings in maybe a week or two or a month and have millions of data points. 

Aaron Rice  17:08

One of the other advancements that's been huge is, as mundane as it sounds, the increase in storage space. And so being able to not only have these massive datasets, but store them and share them. So we've got nearly two petabytes of audio data in our lab at Cornell. Other colleagues in the field have somewhere between two and five petabytes of audio. The National Oceanic and Atmospheric Administration through their National Centers for Environmental Information passive acoustic data portal has a 15 petabytes server in Boulder, Colorado, where they're making some of these large passive acoustic datasets publicly accessible. And so by having and being able to host large scale data, so I had talked earlier about the ability to repurpose datasets for different uses. Now, you don't need to have access to the ocean, or have access to advanced instrumentation. Anybody around the world can download these really large datasets and analyze them for their own scientific or conservation applications, which is really exciting. 

Aaron Rice  18:29

And so what's happened to with some of the advancements, both with analysis, the storing, and going back to the recording technology, is the costs on all of this are decreasing substantially. So 20 years ago, 30 years ago, there were limited groups of institutions that have the ability to build recorders, deploy recorders, and analyze audio data. Now you can buy hydrophones for a couple hundred bucks, or you can buy an archival underwater audio recorder for maybe 1000 or 2000, or in some cases 150 USD, and so the reduction in cost, combined with the increase in technological capabilities, is having the transformative impact of democratizing the field of bioacoustics. So you don't need to be at a US Research 1 university and have a staff of engineers and biologists to do this. Pretty much anybody now can buy a recorder. They can use their smartphone. They can download open-source. publicly available detection algorithms and have similar capabilities to those of us sort of in the university space. And what this enables now is for people around the world to be able to utilize bioacoustics as a very accessible and data-rich approach to include in different conservation efforts. 

Kat Setzer  19:41

Awesome. So everybody can be an acoustician if they want to be.

Aaron Rice  19:45

Ideally, if they're listening to this podcast, I'd like to think they are already. 

Kat Setzer  19:48

Yeah, I mean, right, true. So actually, one question I have, just based off of what you're just saying, and it just got me thinking. So in the article you talk about, like, one of the limitations right now is that battery power isn't advancing at the pace that the other technological advances are. Are there other limitations in technology currently that are preventing some of the leaps forward, or hindering some of the leaps forward? 

Aaron Rice  20:13

Yeah, so it's usually... the technology constraint trifecta is power, data storage, and communications. And so batteries are definitely a constraint. We deploy some recording devices with anywhere between three and, like, fifty individual batteries. If you're continually swapping recorders and replacing batteries, that has a cost to it. The limitations of trying to travel to far-flung locations with lithium batteries represents constraints with either shipping or flying with batteries. And so battery technology, as it advances, is enabling longer and longer recordings, but we're very much limited by the existing available batteries. 

Aaron Rice  20:58

On the storage space side of things, a lot of the recording devices now are recording to either SD cards or micro SD cards. And those range anywhere between, you know, on the order of 100 gigabytes or so. But now we're starting to see microSD cards that are a terabyte in size. And the larger the storage size on an SD card means either the longer a recording device can record until the memory is full, or it can record at a higher sample rate. And so the ability to have a wider array of taxa that you can pick up just due to increases in sample rate, and the operational frequency bandwidth that you can look at. Now you can do surveys for frogs, but you're still getting birds, and in on those recordings, if the sample rate is high enough, you may be able to get some of the higher-frequency calling insects or even bats. So the increases in storage size are a big help. 

Aaron Rice  21:55

And then on the communications side of things, as we start to think about conservation applications of acoustics, where some degree of urgency is warranted to have timely conservation interactions or implementations or response. So the traditional, I use this term "archival recordings," and what that means is that we don't get to look at the data from the recording device until we go out and visit it and either swap SD cards or bring the recorder back to the lab. But what's emerged over the last decade or so is this idea of real-time passive acoustic monitoring. And what this is, is where you have a recording device with an onboard detection approach for a particular species or sound of interest. And then it is able to transmit detection events through satellite networks, Wi Fi, or cellular networks, back to a central server, and a lab group or office that can then evaluate the pattern of those detections. And what that enables is near real-time review of data and the ability to implement conservation interventions on a very short timescale that doesn't require devices to come back after a period of months. 

Aaron Rice  23:12

Now, you can imagine that real-time approaches are great if you're recording pretty close to urban environments or places with good connectivity. As you get farther and farther away, and more and more off the grid, trying to beam those data back gets either more challenging and/or more expensive. And so, the idea of if you're recording underwater and you want to have real-time relay of the data, well, that requires a surface expression to be able to pick up satellites. If you are recording in very, very dense tropical forests, that forest canopy actually may prevent the recording device from being able to connect to satellites. And so as you might imagine, the Wi Fi conductivity, or cell conductivity, is going to be extremely limited in very, very remote locations. And so it's a function of how can we optimize that level of conductivity at a way that's affordable to be able to do real-time based monitoring in places that need it in a level that is both affordable and effective. 

Kat Setzer  24:21

It's interesting, too, because the places that are more remote and thus have less connectivity are probably the places also where you'd want to do more monitoring because there's probably more creatures there that you would want to monitor, like in a rainforest. 

Aaron Rice  24:34

Yeah, absolutely. 

Kat Setzer  24:35

Yeah. Okay, so let's go back, because we talked about all of this, the availability of data and equipment, software, and that kind of thing for the average person who is not connected to a United States research institution. So what sort of skills are necessary for a person who is interested in getting into conservation bioacoustics?

Aaron Rice  24:57

What's fun to think about in this kind of question is how much my answer would change if I was to answer ten years ago versus now. And so ten-plus years ago, I'd say, "Oh, you want to learn to do acoustics, you need to have some degree, some expertise in physics. You need to know computer programming. If you want to do sound propagation, that's some really complicated math that's going on. Oh, and by the way, you need to understand animal behavior, animal communication, ecology. And it's also really helpful if you can do some degree of computer programming, and learn the engineering skills to build your own recording device." And as you might imagine, that's a whole lot of things for any one individual to be able to do. 

Aaron Rice  25:43

The trend that we see in the progression of science over the past couple of decades parallels what we see in the field of acoustics, where, as I tell my students, now, science is very much become a team sport. So rather than one individual having to master absolutely everything to carry out their research program, what's a much more effective, and I would argue fun, way to do things is to really have a solid team of collaborators. So no one person needs to be able to do everything themselves. And instead, you can have people with high degree of specialization in a particular area, working with folks with complementary skill sets, to really be able to do everything. 

Aaron Rice  26:26

And so the skills that I would say that are needed now in conservation bioacoustics... Certainly, the engineering and software development, those are always in really high demand, because, comparatively few people can do that. But I think more importantly, some of the skills that are needed are really on this, what we call the soft-skill side of things, where it's curiosity about the natural world, and attentiveness to the needs of stakeholders and regulators for water conservation needs, for particular habitat or species in different parts of the world. It's having the persistence and patience, to grind through large datasets, and the resilience to stick with it when something goes wrong. 

Aaron Rice  27:10

And I think above all, it's some degree of passion for one's efforts. You can imagine that if you're an AI programmer, you know, certainly at a college, sometimes at a high school, you can go into the private sector and be making a really healthy six-figure salary. In the world of conservation biology, very rarely does it compensate at the same level that Silicon Valley tech companies can, yet we still need the same expertise. And so a lot of the people that we work with, they don't care about the money. And they're very passionate about what they're doing. They're committed to the mission of conservation. And so it's really sort of that labor of love. And trying to understand and protect nature, through the perspective of sound is probably the the skills or the you know, the temperament, that is really one of the prerequisites for conservation bioacoustics. 

Aaron Rice  28:00

But certainly, on the bio- side of bioacoustics, it's the idea of being able to understand, aspects of animal behavior, being able to have fine attention to details of when you start to see changes in patterns of behavior over space and time. It's the creativity and broad thinking to leverage knowledge from one particular situation and apply it to another and use that appropriate level of scientific inference to help inform how do we tackle a problem? Or how what might we either answer or contextualize the data that we're getting? And so, what we see is within bioacoustics, and the combination with conservation, is a wide range of skill sets that are extremely helpful. And where we are as a field now is, I would argue we wouldn't be as successful if we didn't have this wide diversity of skills and contributors to go after these really big picture, and particularly important questions in an era like the Anthropocene.

Kat Setzer  29:04

Where do you think conservation bioacoustics is headed? And I know we kind of talked about this already, but what challenges do you think the field faces?

Aaron Rice  29:12

So I'm admittedly biased as an acoustician, and where I think conservation bioacoustics is headed is increased reliance, or an increased awareness of how the recording and analysis of sound can continue to help inform or solve a lot of these conservation challenges. I think the big challenge the field faces... Yes, there's the technical hurdles, those are non-trivial, but those are advancing. What I think the biggest challenge is for the field is the uptake in acoustic information into a broader audience. So, when we talk about things like full-scale-amplitude dBRMS, a regulator doesn't know what that is, or they may not. We go from a really technically intricate field with very precise physics-based definitions of measurement of sound and the environment, and the challenge is being able to translate that to a non-physics-based argument or audience. The idea. one of the things that really constrains the uptake of acoustics is that many regulators or stakeholders think that acoustics is too esoteric, or it's not really wide ranging, because they don't understand, what the data actually means or what you can do with it. And so that challenge of being able to translate a jargon-laden field into sort of more mainstream, less-specialized terms is very much an art and a skill that you're now seeing utilized much more elegantly now across a wider range of practitioners than we saw many years ago. And so, yes, we need the physicists, we need the tech developers, we need the biologists. But what we all need them to be able to do is speak to people outside their field, convey the importance of bioacoustics in conservation, and being able to really translate that to scientific and non-scientific audiences alike.

Kat Setzer  31:18

So the need for science communication, or folks with a skill in science communication is really important at this point. 

Aaron Rice  31:26

Absolutely. Well, and to that point, too, for so much of us within the US, but the same is true in the EU and other areas of the world, is that we rely on government funding to do our research, and the way that government funding happens, idealistically speaking, is that the broader public and taxpaying community recognizes the value in science and recognizes the importance in managing and preserving protected species and habitats. And so the ability to translate the societal need for science is certainly not unique to bioacoustics. But the urgency in something like bioacoustics is making it, very clear that it's not just limited to really, really limited-use cases, and is not overly complex or specialized, but has wide-ranging application for the benefit of scientists, stakeholders and broader society.

Kat Setzer  32:21

Right. Right. That makes a lot of sense. So in your article, you mentioned that conservation science runs the risk of not being integrated within local communities. How do researchers ensure that they integrate their work with the community's needs and priorities?

Aaron Rice  32:35

So this is something that I, that is a really exciting opportunity to think about. And some of it is involved, where you see the lexicon of theory of change, and how it comes to conservation. And first and foremost in that is engaging with local stakeholders and partners to identify what those local needs are. So I do a lot of work with coral reef acoustics around the world. And as you might imagine that Ithaca, New York, there are shockingly few coral reefs here. 

Kat Setzer  33:04

Yeah. 

Aaron Rice  33:04

And so what that means is that I need to go to different places and engage with communities that actually have coral reefs. And instead of me sitting in an ivory tower pontificating on what I think is useful, or what I might be interested in, that's completely disconnected from local communities that are reliant on fishing or reliant on research ecotourism. And so what that means is for me to understand what's actually important or what's actually urgent is that I need to go to those far-flung places and engage with leaders and practitioners, NGOs, government agencies, students, stakeholders, communities to say, "What are your needs? How can we help?" This is not limited to the marine environment. This is true in all ecosystems, and sort of taxonomic areas around the world, where there is an interest in the conservation of nature. And recognizing that local communities have a significant amount of expert knowledge. And this falls under the heading of traditional ecological knowledge, where it's being able to integrate these communities; take their decades, centuries, or millennia of knowledge about study systems; and identifying if and how we can bring something like acoustics to help solve some of their challenges. 

Aaron Rice  34:28

Some of the other difficulties, too, is the idea of taking really sophisticated and expensive instrumentation to different places means one of two limits, either the ability to afford a particular piece of technology, or having the expertise to be able to use it, or to analyzing data coming off of it. And so in addition to identifying the needs of local stakeholder groups, the other really big component is to increase local capacity through training. And so it's not that people in low-income countries around the world need to figure out how they can afford to get to an institution to receive formal training in conservation bioacoustics. Instead, it's through outreach efforts, nontraditional or informal education, citizen science efforts, the ability of workshops, where local individuals in different communities can learn the tricks of the trade in bioacoustics and start to do it themselves. And so if people can learn how to identify what type of recorder is useful, how to use it, how to analyze the data, we can then start pointing them to, "No, you don't need the $5,000 recorder. Here's one for 50 or 100 bucks." Or, for so many of these communities, a lot of people are really tech savvy. And so we can say, "No, you actually, whether you realize it or not, you have the ability to build this yourself through open-source hardware," or maybe it is a low-cost off-the-shelf recorder. And here's the piece of freeware software that you can download. That's approachable. And you don't need to do command-line programming to use it. You can do this workflow for pretty low cost, or in some cases free, and being able to train individuals in how all these pieces of the conservation framework fit together using different bioacoustics technologies.

Kat Setzer  36:26

That's so cool. So can you recommend some resources for folks who want to get involved with collecting data as citizen scientists?

Aaron Rice  36:32

Yeah, absolutely. So through organizations like the Acoustical Society of America or the International Bioacoustics Council, there are data portals or links that basically provide an understanding of what are the different software that's out there, what's free, what's easy to use. You're starting to see different repositories of animal sounds, whether that's through Cornell's Macauley Library of Natural Sounds, or xeno-canto, or the British Museum, or CSIRO in Australia. There's a wide variety of sound repositories that people can start to understand and experience what different animal sounds like. In many cases, those sounds can be downloaded and used to train automated detection approaches, through Google packages like TensorFlow. We have developed a multispecies AI detection framework called BirdNet, which you can find at birdnet.cornell.edu. And so there are all of these different places around the web, where the different aspects of bioacoustics can be readily accessed. 

Aaron Rice  37:41

The company Open Acoustic Devices, which is a spin out of Cambridge, does open-source hardware. They produce the AudioMoth and the HydroMoth recording devices, which you can download the schematics and build yourself and just buy the parts, or you can buy those recorders from Open Acoustic Devices at a significantly lower cost than recording technologies, many years might have cost. 

Aaron Rice  38:04

But that being said, there's also an opportunity for things like citizen scientists to be involved. So you can take your smartphone, and you can download the BirdNet app. But there's also things like through Worldwide Soundscapes Program, or other acoustic data collection initiatives, where even being able to record sounds through an app through your phone and upload it to the Cloud helps provide either different records of sounds and habitats around the world, or if you're able to identify a particular species, you can provide training data to algorithm developers for creating better and more accurate AI models. And so there's the ability for either people that are sort of formally trained scientists to incorporate bioacoustics in their workflow through these different resources online or different institutions, or there's ways for citizens scientists to getting involved to be able to contribute to the collection, analysis, or model development of bioacoustics.

Kat Setzer  39:07

Awesome. Well, and we can share some of these links to resources in our show notes, too. So hopefully, some of our listeners decide to get more into conservation bioacoustics. Do you have any other closing thoughts? 

Aaron Rice  39:19

Yeah, so I think we're really at this exciting point with bioacoustics and acoustics more broadly, where the field is growing so quickly. In my arena of fish bioacoustics, 10 or 15 years ago, there was maybe 20 people around the world that did this, and it was a pretty small community. And now it's in the many hundreds of people getting involved. 

Aaron Rice  39:43

The ability that I can, go out to a classroom or talk to somebody on the street, and and talk about fish acoustic communication. And rather than getting really weird looks and being like, "What are you talking about?" Now, people say, "Oh, I know what noise pollution is," or, "Yeah, I know how whales or fish are impacted by sound." And so there is this broader awareness of the science of sound, and how sound can be used for informing conservation strategies. And so there's this really great societal opportunity to expand the use of bioacoustics, both with a number of applications as well as the people getting involved. And that's, really exciting being within the field and trying to help promote its increased awareness and usage. 

Aaron Rice  40:30

I think the other thing too, is the field is transforming so quickly, in really positive ways, where the idea that we have technologies now, whether it's BirdNet, or some of these other platforms that were unthinkable even five years ago, really gives us pause to, with some degree of excitement, think about what's down the road in months or years ahead of us. How's the field going to continue to change? How can we incorporate things like bioacoustics into other large-scale data aggregation approaches, you know, think remote sensing and satellites? And not that we're putting microphones on satellites, per se, but how can we start to look at patterns of bioacoustics at continental scales? How can we listen to the entire Earth to understand what's happening, how our animal populations changing? And how can we intervene to alleviate human impacts on a rapidly changing planet?

Kat Setzer  41:28

Yeah, it's really exciting to think about how this field will grow as technology progresses, as more people become aware of the role of acoustics in our world, and just that there's so much information that can be gleaned just from the sounds in the environment. Thanks so much for taking the time to speak with me today about this burgeoning field. 

Aaron Rice  41:49

This has been a lot of fun. 

Kat Setzer  41:50

Have a great day. 

Aaron Rice  41:51

Thank you. 

Kat Setzer  41:52

Thank you for tuning into Across Acoustics. If you would like to hear more interviews from our authors about their research, please Subscribe and find us on your preferred podcast platform.