ecoSound-web: an open-source, online platform for ecoacoustics

Passive acoustic monitoring of soundscapes and biodiversity produces vast amounts of audio recordings, but the management and analysis of these raw data present technical challenges. A multitude of software solutions exist, but none can fulfil all purposes required for the management, processing, navigation, analysis, and dissemination of acoustic data. The field of ecoacoustics needs a software tool that is free, evolving, and accessible. We take a step in that direction and present ecoSound-web: an open-source, online platform for ecoacoustics designed and built by ecologists and software engineers. ecoSound-web can be used for storing, organising, and sharing soundscape projects, manually creating and peer-reviewing annotations of soniferous animals and phonies, analysing audio in time and frequency, computing alpha acoustic indices, and providing reference sound libraries for different taxa. We present ecoSound-web’s features, structure, and compare it with similar software. We describe its operation mode and the workflow for typical use cases such as the sampling of bird and bat communities, the use of a primate call library, and the analysis of phonies and acoustic indices. ecoSound-web is available from: https://github.com/ecomontec/ecoSound-web


Introduction
Automated passive acoustic recording methods are powerful means for monitoring biodiversity and the environment in ecological research, i.e., the field of ecoacoustics.The resulting soundscape recordings -comprising all sounds recorded in a sea-or landscape 1 -present new opportunities for ecologists.However, they yield huge amounts of data that are challenging to manage 2 and to analyse for extracting their ecological information -such as biodiversity, human activities, or geophysical events.Overall, soundscape ecologists require a dedicated tool that allows for such a comprehensive workflow 3 , and which aligns with FAIR research principles 4 .
Methods for the annotation and analysis of audio recordings still undergo rapid development.Annotations are increasingly generated with automated methods 5 to forego laborious but common manual annotation by humans.However, even reference machine learning tools such as BirdNET 6 require post-processing to yield usable results.More importantly, sound source identifications from humans and machines need to be cross-checked, by peers or experts, who rely on reference recordings found in sound libraries to ascertain the identification of sound sources 7 .Alternatively or in addition to taxonomic annotation of recordings, soundscapes can be characterised with automatically-computed acoustic indices that can measure spectral and temporal variation, entropy, or complexity, and be linked to biodiversity metrics [8][9][10][11] .General acoustic feature sets can also be used to detect anomalous sound events in an unsupervised manner 12 .In marine ecoacoustics, annotating and quantifying the temporal proportion of phonies (i.e., sounds of biological, geophysical, and human origin) is well-established 13 , and the sound pressure levels from calibrated equipment are a common metric for studying noise impacts on biological activity 14,15 .Finally, in bioacoustics-or ethological studies, but also for the identification of bats 16 and soundscape characterisation 17 , the target sounds need to be analysed further by measuring their properties in the frequency-time-amplitude space 18,19 .At the time of writing, no software integrates all these different data processing stages into a consistent, integrated workflow for ecoacoustic projects across realms, taxa and regions.Reference sound or call libraries are also still scarce for particular species groups 2,20 , even though recent advances were made for Orthopterans on Xeno-Canto 7 (additionally to well-studied birds), and bats on ChiroVox 21 .
Software tools that handle audio data need to be built sustainably to benefit a large user base in the research community and to stimulate research 22 .While the majority of tools are free, few are online-based, many are specialised on specific taxa, realms or regions, only some are open-source, and most cover only parts of the workflow described earlier.It is essential to have free tools that all researchers and practitioners can use, irrespective of their budget constraints.Also, only open-source projects, in conjunction with long-term vision and funding 22 , guarantee that they can be continuously developed to keep up with the pace of technological progress, that they stay accessible over time, and that the actual functions are transparent and replicable.Accessibility, which is essential for international collaboration and verification of ecoacoustic data 23 , also requires online solutions that are mostly independent of operating systems or commercial software.Finally, tools that integrate multiple steps of the workflow outlined earlier will be inherently less complex for users, more practical, and more replicable than separate, specialised solutions.In a nutshell, the field of ecoacoustics requires an open-source, online, comprehensive software tool.
Here, we first provide an up-to-date overview of software tools available for ecoacoustics.We then introduce ecoSound-web: an open-source online platform for ecoacoustics, designed and built by ecologists and software engineers (for the related GitHub project see: https://github.com/ecomontec/ecoSoundweb).Currently, ecoSound-web can be used to 1) upload and organize soundscape recordings within collections; 2) to manage users and access to collections within dedicated projects; 3) visualize them on maps and timelines; 4) play back, navigate, and filter their sound and spectrograms; 5) create and peer-review manual recording annotations; and 6) measure sounds and compute acoustic indices.ecoSound-web was forked from BioSounds (c.f.article version 1).We detail the structure and functionality of ecoSound-web in the following and announce our development goals.

Amendments from Version 1
Changes from version 1: • ecoSound-web replaces BioSounds • added projects management to organize collections, user management for project managers • acoustic indices can be computed with scikit-maad • bio-, anthropo-, and geophony can be annotated and Scikit-maad 1.3.12 35software for sound and image processing, a MySQL 36 database for organising the data (Figure 1), a RabbitMQ 37 queue for file processing, Plupload 1.5 as a visual file upload tool 38 , GADM as administrative regions for the sites 39 , JQuery UI 1.12 40 , JCrop 0.9 41 , Bootstrap 4.3 42 , Leaflet 43 , Timeline.js 44, Bootstrap-selected 45 , Jquery.cookie 46 , DataTables 47 and the Symfony 4 process component 48 for managing the scripts execution.Further Python libraries used are: Numpy 49 , Pillow 50 , Audiolab 0.8 51 , Matplotlib 52 , SciPy 53 and Scikit-image 54 .We containerized the project using Docker 55 , which spares software developers the time for installing libraries, the database, and configuring the server.This setup allows developers to run the project on their machines quickly and free of typical installation issues like library version incompatibilities.
Audio visualization and playback.

Operation
Ecoacoustic workflow.In ecoacoustics, a general workflow is currently not comprehensively defined.We therefore combine insights from different literature sources and our own experience to propose a general workflow as follows (Table 1): 1) Data management: Acoustic data need to be backed up, archived, and organized according to space, time, and other meta-data 56 .2) Signal processing: Recordings can be amplified, re-sampled, split, filtered, compressed, etc. for facilitating the workflow 57 .3) Audio navigation: Sound recordings can       2A); the recordings listed in the collection are dynamically filtered and clustered based on the current map extent.Collections can be displayed as 1) a list view with larger spectrograms, descriptive data, and a simple audio player, which is particularly suitable for call libraries (Figure 2B); 2) a simple gallery view displaying spectrogram thumbnails (Figure 2C); 3) a timeline view where recordings are ordered by sites on the Y axis against a navigable time axis on X (Figure 2D).
Users.ecoSound-web has two registered user classes with differing privileges: normal users and administrators (Figure 3B).Administrators have privileges for creating, accessing, editing, and deleting projects, collections, recordings, tags, and users.They can transform users into administrators, or give management privileges to normal users for specific projects so they can act as project managers.Project managers have privileges for creating, accessing, editing, and deleting collections, recordings, tags, and users belonging to their projects.They can give tag view and review privileges to normal users.Normal users have privileges for creating, accessing, editing, and deleting their tags belonging to their collections.If applicable, they can view and review tags of other users as determined by their privileges, and thus act as peer-reviewers.

Spectrogram player.
Recordings can be opened in the spectrogram player (Figure 4).Spectrograms are visualisations of sound where sound amplitude is shown in color or greyscale tones, time is shown on the X axis, and frequency is displayed on the Y axis.Audio channels can be displayed separately.The current spectrogram image and the compressed audio recording (MP3 for audible sound, OGG for ultrasound) can be downloaded.The spectrogram player offers various functionalities for tagging sounds: it is possible to play back sound (at speeds between 0.05 and 1), filter frequencies outside of the current spectrogram view, navigate the spectrogram (zooming per selection, shifting frame sideways, standardized playback at specific display densities), annotate spectrogram regions (creating tags per selection, assigning them to phonies, sound types or soniferous animal species, reviewing and hiding them), label recordings with pre-defined and custom labels, and perform sound analysis (using alpha acoustic indices).Spectrograms are generated after every navigation command, and audio is downloaded on-demand for playback.

Use cases
Bird community analysis (Manual annotation and peerreview with different user privileges) Soundscape recordings can be annotated manually for bird vocalisations (or any other sound-producing organisms), and their annotations peer-reviewed by expert ornithologists, as exemplified in the collection "Upland plots dry season 2013".Users can scan recordings visually and aurally using the built-in reading mode, which zooms into the recording to display 15 pixels per second over the entire frequency range (additionally, custom display densities can be set), and enables continuous playback between spectrogram frames.For stereo recordings, the left or right channel can be selected for visually checking vocalisations that may be audible on another channel than the one currently visible.All avian species can be tagged/annotated based on rectangular spectrogram selections along the frequency and time axes.Users can choose species from the integrated species list based on the IUCN Red List taxonomy, and links to Xeno-canto and Google image searches to help the user with identification (Figure 5).Unclear identifications can be marked as uncertain and additional comments be given.Tags can be designated as reference recordings to be included into future reference collections.Tags can be zoomed into and sharing links can be generated and copied to the clipboard.Any current audio portion can be downloaded as a spectrogram or audio file for sharing with collaborators.Detection distances are estimated by using the distance estimation function (Figure 4) that enables full-spectrum viewing and playback of the tags based on a spectrogram of the first 30 s of the tag.Additional audio recordings of test tones emitted at known distances are required to help human listeners estimate detection distances in an unbiased way 60 .
Acoustic recordings can be verified and validated on multiple levels to produce accurate datasets 61 .In ecoSound-web, tags can be peer-reviewed to validate species identifications and auxiliary data (e.g., distance).Users with reviewing privileges can either accept species identifications, revise them by suggesting other species, mark them as uncertain, or reject them by marking the annotation for deletion (Figure 5).Administrators can also check the listening durations of each user for each recording to verify that all recordings have been listened to in entirety,   and to extract a measure of the sampling intensity.Finally, it is possible to train annotators -after granting them tag viewing privileges -with example annotations of other users.Subsequently, their performance in comparison to already annotated recordings, after revoking tag viewing privileges, can be tested.After the validity checks have been run, users can export the tag data through the administrative interface as a CSV file for further statistical analysis.
Bat community analysis (working with ultrasound and using the Chiroptera reference collection) Ultrasonic soundscape recordings can be similarly analysed for bat vocalisations, as shown in the collection "Bat point counts and automated recordings 2019".However, bat call annotation and analysis present specific challenges.First, bat calls are very short and rapid in succession (units or tens of milliseconds), which is why ecoSound-web generates new spectrograms after zooming, based on precise spectrogram selections.Frequency filtering is enabled by default, so that users hear only what they see on the spectrogram, but can also be disabled.The Fast Fourier Transform (FFT) window size can be set for all recordings accessible to the user (in the administrative interface) and for each recording (Figure 4) to visualise bat calls better by choosing the ideal trade-off between the frequency and time resolution of the spectrogram.Finally, as ultrasound is not audible, users can adjust playback frequency (continuously between 0.05 and 1) with the playback speed slider to make ultrasound calls audible.
Bat species identification is challenging, as calls from different species can be similar.Additionally to species, custom tag identities can be used for bat sonotypes (i.e., bat call types with similar characteristics across different bat species) 62 .Exact measurement of bat call features usually determines the assignment of bat calls to specific species.Using the clipboard button (Figure 4), users can copy the frequency and time coordinates of currently-selected bat calls to derive the start and end frequency, as well as call and call interval duration.Additionally, a dedicated button computes the frequency of maximal energy of the current spectrogram, a metric used for species identification.For species that have taxonomically unequivocal calls, users can refer to the reference collection "Chiroptera" to corroborate their identifications.As manual distance estimation of bat calls is impractical due to their mobility and the fact that humans cannot intuitively estimate distances of usually inaudible sounds, tags' distances can be marked as not estimable.
Primate bioacoustics (working with reference sound libraries) Reference calls, i.e., example recordings of a animals' vocalisations, can accelerate the detection of the call (visually or algorithmically) and facilitate the verification of the species identities found in soundscape recordings.Large reference call libraries already exist for birds (Xeno-Canto) and bats (ChiroVox) but are lacking for many other sound-producing animal groups.Available calls from more general libraries such as tierstimmenarchiv ("tierstimmenarchiv") contain mostly recordings of captive animals or animals with unknown geolocations, resulting in unclear taxonomies.For primates, acoustic communication has been studied in detail 63 .However, the potential of passive acoustic monitoring has only recently been acknowledged 64 and applied to analyze, e.g., individual caller identity in orangutans 65 , occupancy in chimps and gibbons 66,67 or density in fork-marked lemurs 68 , and reference calls have yet to be openly published.
Primate call repertoires range from 7-8 call types in ancestral primates 69 to more than 30 individual call types in bonobos 70 .Many primate vocalizations transmit indexical cues -specific call signatures linked to individuality, sex, population, or species -and they are distributed over a wide range of frequencies extending in the ultrasound field for some basal primates 69 .This diversity of behavior underlines the importance of their vocalizations 71 .Although most primate call types are probably used in social contexts over relatively short distances, there is extensive evidence for loud, long-distance calls (several hundreds of meters), that are usually used for intergroup spacing, territorial defense, alarm situations, or as mate advertisement calls 72,73 .This provides additional arguments for analysing soundscapes, which can record calls of primates over large areas, to improve future primate population monitoring.However, the lack of publicly available primate reference call libraries slows down its development.Therefore, we initiated the first public primate reference call library based on georeferenced field recordings and annotated vocalisations.Vocalisations are classified into 13 behavioral contexts, such as affiliative, agonistic, contact, or alarm call (see online Guide).The collection is shown in the public "Reference collection Primata".DOIs of the respective publication can be assigned to the reference recordings, and Creative Commons licences be chosen to describe usage rights.Distance estimation and collaborative tagging can be used as described above.

Analysing soundscapes holistically (phonies and acoustic indices)
Soundscapes contain sounds of organismal, human, and geophysical origin 3 , and their acoustic diversity correlates with biodiversity 74 .ecoSound-web allows the annotation of sounds with these three different phonies: biophony (sounds of organismal origin), anthropophony (sounds of human origin), and geophony (sounds of geophysical origin), as well as an "unknown" category.Phony annotation is exemplified by the "Demonstration soundscapes" collection of the Worldwide Soundscapes project on ecoSound-web.Phonies are at the highest level of the sound typology, and only biophony tags allow the specification of the sound-producing species.Within phonies, sound types can be specified, but currently, no systematic typology of sound types exists, so only pre-defined and custom labels are available.In addition, any currently generated audio portion and channel can be analysed with alpha acoustic indices provided by the integrated python package scikit-maad 10 .Parameters can be input for each function, or left at their default values.Results can be saved by each user and downloaded as a CSV file from the administrative interface (Figure 3A) for further analysis.

Future development
We are continuously expanding the functionality of ecoSoundweb.Open-source code is a requirement for future development and maintenance.However, it is not a guarantee for a sustainable project either, as some of the open-source automated sound classification tools compiled by Priyadarshani et al. in 2018 5 are currently discontinued.In the near future, we will implement the following functions: In ecoSound-web, we implement best coding practices and use development tools, like Docker, to facilitate developers' work and help them engage in collaboration.We welcome new collaborators to support the project development who could become co-authors on subsequent versions of this article.

Conclusion
ecoSound-web can be used to store, organize, visualise, play back, peer-annotate, analyse, and share soundscape recordings, tags, collections, and projects online, publicly or with specific users.The recordings can be analysed collaboratively for quantifying soniferous animal species activities such as birds and bats in ecological studies.Furthermore, phonies can be quantified in time, space, and frequency, and alpha acoustic diversity indices can be computed.ecoSound-web has already been used successfully to analyse bird communities 75 , to measure bat activities 76 and to host reference recordings 68 .Regionand taxon-specific reference collections can be created, like the anuran and primate call collection that we host 68,77 .
The field of ecoacoustics and soundscape ecology requires a software tool that standardises and unifies the management and analysis of acoustic data.Although we present one such tool, in the long run, the field is overrun by a multitude of mushrooming projects with unique advantages, for which we compiled the present overview (Table 1).The sheer number of tools impairs their discoverability, the standardisation of workflows, and their adoption, which is why we decided to integrate an existing tool for the acoustic index analysis (i.e., scikit-maad), as well as a broad thematic scope to include projects from any region, taxon, or realm.A funding and interest-related partitioning and specialisation of the available research platforms (e.g., WildTrax for terrestrial Canada, OPUS for marine Germany, etc.) may be counteracted by APIs enabling inter-operability, and in the broader sense, the FAIR research principles 4 .Ultimately such developments would stimulate reproducible, cross-realm, and synthetic research based on passive acoustic monitoring methods, potentially even across the Earth System Sciences, where not only ecological, but also geophysical phenomena are analysed.

Erin M. Bayne
Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada Biosounds is a very important step forward in the field of bioacoustics.Being able to manage large volumes of digital audio files and the various data that result is a large task that requires "big data" tools.Biosounds is a great step in this direction that continues on from past efforts.I greatly appreciate the efforts the authors have taken to continue developing tools that already existed.Building off of those tools and bringing them together into an easily setup system is a big advance.
A gap in this particular draft of the paper are other similar efforts that do exist.For example, the group I work with has developed Wildtrax (www.wildtrax.ca)that has been operational for several years in Canada.This online system is used by partner agencies in provincial and federal governments, not for profits, industry, and academia.It has similar processes to Biosounds in the area of bioacoustics while also providing a platform for the storage of digital images taken by remote cameras.Including this effort as part of the comparison seems warranted.The key difference is Wildtrax is a centralized database system with the goal of sharing data amongst users Canada-wide rather than have each group setup their own server etc.It too is in development and has many things in common with the list of things Biosounds would like to see developed.The key difference seems to be that we have centralized the process and focused on users bringing their data to one place rather than managing things individually.

Methods
"by computing a fast fourier transform" -what are the parameters for this?And why were they chosen?Are they customisable / do they adapt based on recording parameters?
○ "Soundscape collections, due to their larger size, can be integrated up to a manageable size" -giving an indicative size in GB/TB is crucial for readers to assess whether this tool is suitable for their own projects.
○ "upload recordings in most common audio formats" -please detail exactly which formats are supported.
○ "MP3s of the audio file are generated after insertion into the database" -are the original uploaded audio files retained on the server (e.g., in the case of raw WAV files being uploaded)?Can the users download these back at a later date, or only MP3s?How are the MP3s generated (which codec) and at which compression level?
○ Use-cases "distances are estimated in a standardised way" -how?Using spherical sound absorption assumptions, or by other means?Also, how is distance estimated without knowing the typical source SPL value of a species' call?
○ "export the tag data through a MySQL database" -are users (not administrators) also able to access this data?It would also be useful to add CSV export option for those not so comfortable with SQL DBs.
○ "bat morphospecies …. named with single letters from A to J" -you should either detail how these morphospecies differ (what are the identifying call characteristics that places a bat in B for example), or if irrelevant leave out this level of detail and just mention that morphospecies are supported too.
○ I also had a play around with the live demo running at https://soundefforts.unigoettingen.de/biosounds/.My overall impression was very positive -the site was intuitive to interact with and things generally worked as advertised.I do have a few very minor recommendations below but appreciate that fulfilling these may be more difficult than the suggested manuscript changes: Opening the player view for a large file can take some time, and it just seems as if the connection has dropped (until finally the page is ready).This is not an issue when going forward and backward within the collection as there is a loading overlay, which makes it clear what is happening.

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When loading a large file into the player view the "play" icon is grayed out until some background loading is done.It isn't clear that this is happening until this is done thoughmaybe a loading indicator in place of the gray play icon would be clearer.

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Once I'd zoomed in on a part of the spectrogram I couldn't return to the original, zoomedout view without refreshing the page.This should be possible.

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When in the player mode there is no indication of sampling frequency or labels on the spectrogram's Y axis.This info can be inferred from the frequency selection box values, but it should be more clearly apparent in my opinion as it is such an important piece of information.If an expert is searching for calls from a specific species, frequency labels on the Y axis can make this a lot quicker.

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When searching through a collection, if you click on a species from the dropdown prompt, the expected behaviour is that the search will be performed.However, instead a search isn't actually triggered until you click the search button manually.The benefits of publishing with F1000Research: Your article is published within days, with no editorial bias • You can publish traditional articles, null/negative results, case reports, data notes and more • The peer review process is transparent and collaborative • Your article is indexed in PubMed after passing peer review • Dedicated customer support at every stage • For pre-submission enquiries, contact research@f1000.com

Figure 2 .
Figure 2. The gallery ( The gallery (C), list (B), and timeline (D) views for recording collections in ecoSound-web, along with the interactive site maps (A).

Figure 3 .
Figure 3.The administrative interface for project managers and administrators.The recording management tab (A), and the user privileges window (B).

Figure 4 .
Figure 4. ecoSound-web spectrogram player.ecoSound-web spectrogram player.Numbers correspond to the following sections: 1: Project/collection/sound name.2: annotating (i.e., tagging) sounds.3: hiding/showing tags.4: panning spectrogram left and right 5: playback mode (zoom to standardised display density).6: audio channel selection.7: overview spectrogram, red rectangle shows current view.8: playback speed slider.9: playback/ pause and stop, time position.10: playback cursor.11: time and frequency coordinates of current view or selection.12: two analysis buttons: copying time and frequency coordinates, exporting frequency of maximum energy.13: zooming into current selection.14: continuous playback.15: frequency filter.16: utilities menu, containing: image and audio download, FFT window size setting, file info.17: tags of different users shown with different colors; reviewed tags with solid border, not yet reviewed tags with dashed border; tags without detection distance with orange shading.18: tag ID and species/sound type appear on click, with buttons for editing, zooming, and estimating distance.19: assigning pre-set or custom label to recording.20: computing alpha acoustic indices 10 .

Figure 5 .
Figure 5.The tag editing window.The phony and sound type selection is remembered for faster tagging.Species, sound distance, individuals, and animal sound type fields are only shown when "biophony" is selected.Sound distance estimation is greyed out because values can only be entered with the dedicated function or declared as not estimable.Green sharing button: copies a URL to the clipboard to open the exact spectrogram region.The entire right pane is only visible to users with reviewing privileges.

1 . 2 .
TensorFlow-based automated detection and classification of vocalisations Expanding sound pressure level analysis and calibration functions 3. Increasing interoperability by linking ecoSound-web to taxonomic databases and ecoacoustic software tools

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Is the rationale for developing the new software tool clearly explained?YesIs the description of the software tool technically sound?YesAre sufficient details of the code, methods and analysis (if applicable) provided to allow replication of the software development and its use by others?YesIs sufficient information provided to allow interpretation of the expected output datasets and any results generated using the tool?YesAre the conclusions about the tool and its performance adequately supported by the findings presented in the article?Yes Competing Interests: No competing interests were disclosed.
Pumilio' project56.This script generates spectrograms by computing a Fast Fourier Transform on the waveform of the audio recording, at a user-specified window size (at 128, 256, 512, 1024, 2048, or 4096).Second, sound playback and speed control use Web Audio API, a high-level application programming interface for processing and synthesizing audio in web applications.It is included in modern browsers to take advantage of the browser resources without requiring any extra media player or library in our project.
The core sound visualisation and playback tasks are handled by two distinct components.First, spectrogram images are generated by the Python script 'sound visualization tool', which was created for the discontinued '

Geographic management Temporal management Amplification Snippet extraction Noise reduction/ addition Resampling Spectograms Waveforms Frequency filteringz Playback Playback rate/ pitch control Manual annotation Automated sound detection Reference recordings Acoustic indices Frequency spectrum Frequency- time measurements Sound level measurements SPL calibration Public projects Collaborative projects Discussion platform/ fora Form to contact contributors Research indices User access Code access Link to code License Software type Interaction Execution Last update Manual
. Overview of currently available software tools for ecoacoustics.We included only ecoacoustics software tools built specifically for ecoacoustics that fulfilled at least one of the overarching purposes of the ecoacoustic workflow.We excluded tools that were not developed in the last 2 years.http://ravensoundsoftware. com/software/raven-pro/ Server installation.ecoSound-web is published in a GitHub repository58and needs to be installed in a web server to run.Instructions and general information regarding the setup for developers and the production server are included in the README file on GitHub.The ecoSound-web installation for local development (in the developer's machine) is facilitated by a Docker setup.We provide a set of Docker configuration files that can also aid the server installation, but the final setup should be carried out by the server administrator (or devOps engineer) of the institution.For server installations without Docker, a step-by-step installation guide is provided in the repository.All projects can be accessed through the "Projects" menu, which provides a public overview.Projects and collections are managed in the administrative interface.Projects can contain public (i.e., open) and closed collections, accessible to defined users (c.f."Users" section).Recordings can be uploaded into collections in most common audio formats 32 .PNG image previews of the spectrograms and MP3s (for audible sound) or OGGs (for ultrasound > 44100 Hz) of the audio files are generated after insertion into the database, while the original audio files are retained on the server (a download feature is planned).Audio recordings can have custom names to hide the original information present within file names.Collec- r-project.org/web/packages/soundClass/soundClass.pdfohun https://www.biorxiv.org/content/10.1101/2022.12.13.520253v1.R https://cran.r-project.org/web/packages/ohun/vignettes/ohun.html Wildtrax https://www.wildtrax.Access.We run an online instance of ecoSound-web 59 where the use cases described below can be reproduced.The website hosts several projects belonging to different research groups.One project hosts public reference collections (i.e., reference audio libraries) for Chiroptera, Primata, and Anura, curated by project managers.Soundscape projects can be created per request.Users can access ecoSound-web (both the existing instance and future installations) via a desktop browser with an internet connection.ecoSound-web works with Windows, Linux, and MacOS operating systems and the most common internet browsers (Firefox, Chrome, Safari), but recordings above 96 kHz cannot be played back in Firefox due to browser limitations.Projects and collections.ecoSound-web organises audio recordings within collections, which are grouped under projects.tions' geographic locations are shown on Leaflet-based maps with an OpenStreetMap base layer (Figure

have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. Version 1
This is an open access peer review report distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Is the rationale for developing the new software tool clearly explained? Yes Is the description of the software tool technically sound? Yes Are sufficient details of the code, methods and analysis (if applicable) provided to allow replication of the software development and its use by others? Yes Is sufficient information provided to allow interpretation of the expected output datasets and any results generated using the tool? Yes Are the conclusions about the tool and its performance adequately supported by the findings presented in the article? Yes Competing Interests:
While the rationale for WildTrax and Biosounds are different, it does raise what I think is a very important point that would help expand this paper.How do we use tools like WildTrax and Biosounds to create international collaborations and data sharing standards and where might this repository lie?This paper is an excellent description of a wonderful tool but how users that download and setup servers, etc., should consider sharing/using data together is underemphasized.By providing this type of tool Biosounds provides the infrastructure to help us start developing this vision but I feel this paper should also include at least a section for how we should discuss something greater through shared centralized repositories that build off initiatives like Biosounds and WildTrax.Whether a country by country nodal structure is an option that should be discussed rather than having individual labs, researchers, or local government departments create their own systems is the next step in determining how we can better utilize the amazing power that autonomous recording devices give us.A discussion of how such a process might be facilitated internationally (i.e. through ornithological societies, bat societies, etc.) would help develop the vision that I think Darras et al. and others envision.Darras et al must be complemented for developing such a useful tool that will undoubtedly improve the field of bioacoustics immeasurably.It is now up to the bioacoustics and wildlife biology fields to determine the best ways of making this data the most useful for the advancement of science and conservation.My primary comment on this paper is simply that it does not include all platforms that I believe relevant and one of those is a tool I am developing that shares similar functionality.I am working in very similar areas trying to achieve a similar objective.My group uses ARUs for a multitude of objectives and needed a tool that could do what is described here.We took a different path than Biosounds but what they have developed is an excellent resource I can see drawing from.

have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.
Table1presents a comprehensive comparison between Biosounds and other tools.However, it is difficult to parse efficiently in its current format, with a large number of factors to consider, and sorting all the options just alphabetically.Maybe sorting from most to least features, or grouping tools in some way would allow for faster comparisons to be made between the offerings.Additionally, wherever it is placed, putting Biosounds in bold would improve the table.

Table 2 ,
whilst again comprehensive, is arguably not too interesting.Picking out the key few differences and presenting them inline in the text may be a clearer way to present this information -readers are perhaps unlikely to read through the entire page long table.The full table could then be left in supplementary materials