Automatically add a spectrogram view to observations with sounds

Ken-ichi, I don’t understand why an uploaded spectrogram is such an annoyance for you…?

Thank you for doing all that research!


Yes, I’ve done this on a number of occasions. What’s the objection?

eta: I’ve done even worse. I used a smaller segment from a longer sound file as the example for the spectrogram to get around the (2) x axis problem.


Observation photos are intended and assumed to be photographic evidence for the recent presence of an organism, i.e. they should communicate what you saw in the field. Not spectrograms, not habitat shots, not pictures of the sky to show what the weather was like, not photos of photos, just actual photos that show someone what you saw, and hopefully look like what others might see when seeing similar evidence for the recent presence of the same taxon. We make that assumption when showing observations photos on the taxon page, when training our computer vision system, when sharing data with partners like GBIF, etc., and all those non-organism shots break that assumption and cause us to use and share inaccurate information (we claim something is a photo of an organism when it’s actually a spectrogram). If at some point we support some way to categorize observation photos or support some other form of ancillary photographic material to be attached to an obs, then that stuff would be ok, but at present we don’t. I realize tracks & signs screw that up and I admit my tolerance for them is a lot higher than it is for spectrograms, but I think that’s b/c they at least show something unique about the organism that helps others learn to recognize it in person (“but what about microscopy” etc etc). Spectrograms are great evidence and really interesting (as are habitat shots, microscopy, most of the other kinds of images that people upload as obs photos), but if we’re not going to distinguish them from photos of organisms then I don’t think people should upload them. Maybe post them elsewhere and embed them in the description or a comment or something.


I’m not sure how to square that attitude with the, well, mantra of ‘connecting people with nature’, and any scientific data being a welcome side benefit. You have expressed this yourself.

So far, my attitude towards observations (others as well as mine) has been that it’s OK to show evidence of any kind. There has been discussion of drawings as you know. If this creates problems for the AI, then the AI should be improved. (Not knowing too much about the technical side of that, my hunch is that it should be easy for the AI to distinguish a spectrogram from a photo.)

But if this is the official position we’ll just have to deal. I won’t go as far as telling others not to upload spectrograms, but I can set my own spectrogram-as-picture observations as ‘no evidence.’ Is this the preferred course of action?


Okay. I don’t understand the aversion to some waves though. Photos are representations of an organism in light waves, and spectrograms are light-wave representations of sound waves. All the waves describe an organism whether we hear them, see them, feel them or are completely unaware of them because human senses can’t detect them. They vibrate nonetheless, and it’s all the same ‘stuff’ :-)


I didn’t say it was an official position. It is my opinion. If we on staff thought this was a serious problem we would build tools to support or suppress these kinds of images, or at least include some kind of statement of policy in the FAQ or the Curator’s Guide. I would personally prefer that people not post these kinds of images as observation photos, but currently we don’t have an official position on them.

This convo has gone a bit off the rails. If anyone has input on better ways to programmatically make spectrograms that accommodate all (or a least most) use cases on iNat, including bats, I’m all ears (yuk yuk).


Thanks for clarifying. It’s too easy to take your word for policy. I am happy to see you’re looking into this.

Back on the original topic, it looks like you’d be all set for audible sound files (max. 44 kHz). You could defer handling of higher sampling rates to whenever the tools become available. Zoomable/scrollable axes may be nice, if that is an option.


Any progress on this? I’ve recently upped my field recording game a little. The iNat app now integrates with my audio recording app (RecForge) mostly seamlessly so that most repeating calls can get reliably captured. I’ve also been playing with BirdNet, mentioned above, with satisfying results.

I feel the pain of @kueda when I first saw spectrograms, but learned to appreciate the hack. In the absence of audio recognition, a spectrograms can train the image recognition… IF everyone used the same spectrogram protocol, IF it didn’t de-train normal images, IF it didn’t cause confusion and distress in a community unfamiliar with them, etc.

I’d love to see the progression continue toward more native support of audio observations and unified spectrogrammetry. Search the forum and audio interest is there. Any movement since the last post here?


Nope, because

I haven’t put any time into solving these problems since I described them, and was sort of hoping folks with more experience processing sound on the command line could suggest a way or tool to do the cropping for 1, and how to create a single spectrogram format (size, px / second to show on x axis, kHz range to show on y axis, etc) for all sounds for 2.


Thanks, @kueda, I know you guys have plenty to work on :) I also hope someone can help out.

Not sure where to recruit from within the iNat community, but maybe there would be some willingness to collaborate from the folks at Cornell Lab of Ornithology or Macauley Library? Maybe Wildlife Acoustics, a for-profit company, might be willing to help out since it could allow their bat detector product to integrate with iNat? Just a few places to try.


Maybe have an “Evidence of Organism” toggle for everything that’s not a photo of the animal itself, and then exclude that from CV learning?


11 posts were split to a new topic: Question about evidence of human activity

I don’t have experience processing sound but I’m wondering if bat recording observations are rare enough relative to other kinds of sound that it could default to eBird-like settings and then have a button to show the full spectrogram? (analogous to the zoom/brighten buttons for images) I’m not sure if insect sounds are more similar to birds or bats.
I guess one potential issue with that is if it means you have to save two images for each recording.


@kueda: My opinion based on somewhat limited knowledge of ML and computer vision is that you already have that problem with “garbage photos” - ones that are misidentified, ones that have insufficient resolution or clarity, ones where the specimen is very small, ones where multiple species are depicted. Yet the algorithms handle it. Suggestion: if a particular image comes back with very low likelihood of being the depicted species, have it autoflagged as “identified species not visible” so that the image is not used, or is used properly, as part of a training set. Then we could include hostplants, spectrograms, weather conditions - parts of the field notes that are desperately needed.

Imagine a world where the spectrogram could be used by AI for bird ID, instead of what happens now – one posts a sound recording, and within a couple of years someone else finds it.


Not to beat a dead horse, but I thought the AI response to my sparrow song was funny:

Like it or not the AI is picking up on spectrograms, and as of now bats beat birds in the spectrogram-to-photograph ratio. Perhaps “spectrogram” could be established as a “pseudo taxon” that the AI learns to recognize, and then never has to suggest.


my experience is that birds are identified fairly quickly on iNaturalist, if they can be identified easily, even if the only evidence is audio.

BirdNET – The easiest way to identify birds by sound. (

there are a couple of videos on that page that give some basic explanation of how they do their thing. when asked if their algorithm could be adapted for animals other than birds, the answer is “maybe… other animals are using other frequency ranges than birds, and it gets more challenging for insects who are using higher frequencies, and it gets more challenging for bats… you need more specialized equipment for that [rodents, bats]… you can’t use your phone for that…”. apparently, you could theoretically leverage their open source code or even hook into their API to develop your own apps.

to me, it seems like it would be a lot of work for relatively little benefit to develop something specifically for birds in iNat, considering other things already exist. if you’re going to develop something that can cover any organism, then that might be interesting, though probably exponentially more challenging.

also, at least right now, the number of observations with sound in iNaturalist is not very large – so there’s not necessarily a lot of data to train on. currently, there are only a little over 144,000 observations with sounds (mostly birds), representing just under 6,000 species. but if you look at how many of these species have more than 100 observations, you’re sitting at around 270 species, and if you limit that to just research grade, you’re down to around 240 species.

a lot of the data submitted is not even actually audio, since spectrograms are technically images, not audio exactly…

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I like this idea a lot. Having spectrograms attached is really useful, and if displaying them from the .wav file isn’t possible, this seems like a reasonable solution.


I dont know if Tadarida Toolbox makes spectograms but it can tell you which species the sound contains. I thougt it was used for online websites in UK en FR.

While this is interesting, I don’t have an enormous amount of trust in automatic sound classifiers (background: I spend about 8 hours a day during the non-field season manually vetting the outputs of the SonoBat classifier and it’s correct some of the time, correct but not confident some of the time, and plain wrong some of the time).

Is your suggestion that iNat implement code for doing “computer vision” on .wav files? That would be interesting, but would still necessitate people confirming IDs to download the .wav file, look at it in a sonogram/spectrogram viewer, and then come back to iNat to add their ID. I often end up doing this when a .wav file is uploaded anyway, but sometimes that step isn’t necessary, and when it isn’t you’ve saved several minutes of steps and therefore can make more IDs. There’s a massive backlog of potentially identifiable acoustic bat observations on iNat, and very few people who both have the expertise and time to work on them. Making it faster and easier to do could help with that.

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You need only a few mammals, crickets and birds so the hit ratio was high.