[HN Gopher] Bird song sonographs show distinct drawing patterns
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Bird song sonographs show distinct drawing patterns
Author : algui91
Score : 178 points
Date : 2021-05-07 09:13 UTC (13 hours ago)
(HTM) web link (soundshader.github.io)
(TXT) w3m dump (soundshader.github.io)
| OmarShehata wrote:
| This is amazing. The GitHub repo has more information too, about
| how the common explanation of how our ears work (isolating sounds
| in an FFT-like-process) may be incorrect:
|
| > Contrary to what you might think, our ears don't seem to rely
| on an FFT-like process to extract isolated frequencies. Instead,
| our ears detect periodic parts in the signal, although in most
| cases those periodic parts closely match the FFT frequencies.
| There is a simple experiment that proves this point:
|
| https://github.com/soundshader/soundshader.github.io#why-acf...
| jcims wrote:
| This is my laymans test for the FFT theory.
|
| Put in earbuds or a headset and (quietly) play sounds that are
| slightly different in frequency (1-10hz).
|
| You will still hear a sort of ethereal beat tone between them
| that's different than the beat you would hear if you were
| listening to the same through speakers. I don't see how this
| would occur frequency-domain perception and it's too present
| (at least in my experiment) to be attributed to bone conduction
| across the skull.
| morelisp wrote:
| https://en.wikipedia.org/wiki/Beat_(acoustics)#Binaural_beat.
| ..
| jcims wrote:
| Whoa! At least that gives me some comfort I wasn't
| imagining it.
|
| I wish I understood some of the neurological explanation of
| how the beats are perceived because it doesn't seem to
| match with my understanding of the explanation of how our
| ears work. If everything is pushed into the frequency
| domain based on the stimulation of different parts of the
| cochlea, where does the time domain beat emerge?
| filoeleven wrote:
| Part of why we evolved two ears is to be able to locate
| sounds within our perceptive field. I think the best
| example is to listen to some recordings made with two
| head-mounted microphones. I like these here; one was the
| closest I've come to believing I was standing in a pond
| while in my own house. It requires headphones to get the
| effect: https://quietamerican.org/field_vietnam.html
|
| There's another component at play too: beat frequencies.
| This happens anytime you have different frequencies
| playing simultaneously. This is a result of simple
| waveform interference. Lots of examples, but I'll never
| pass up a chance to link to Julius Sumner Miller[0]:
| https://youtu.be/7dxkW5bsUgs
|
| So the brain is doing lots of work to integrate the
| stereo "image," in much the same way we can wear 3D
| glasses and perceive depth[1]. Binaural beats reduce
| things down to a more fundamental level: you're playing
| with how your mind integrates the stereo field in a weird
| way, and it produces a beat frequency that does not exist
| in the pulsed air. This may be learned behavior.
|
| [0] I'm eagerly waiting for some music producer to sample
| this video: "all the music fell out", "we should have
| this mechanism called beats", "beats: wonderful!", etc.
|
| [1] I wonder what the effect of rapidly switching the
| left/right components of a stereo image would be.
| Probably nausea.
| jcims wrote:
| The part that doesn't make sense to me is that the
| binaural beat frequency corresponds with the physical
| beat frequency of the sound. So if you got 432Hz in one
| ear and 428Hz in the other, you're going to hear a 4Hz
| beat frequency between the two.
|
| If the cochlea is effectively taste buds for sound, the
| only thing the brain is going to get is which part of the
| cochlea is being tickled. There's no time domain
| information there, just some ambiguous 'pitch'.
|
| If that's the case though, how does the brain know to
| synthesize the 4Hz differential between these two
| frequencies. The 432Hz and the 428Hz aren't making it to
| the brain, just the fact both ears are getting tickled in
| very close but different places.
|
| (Also my dad absolutely LOVED watching JSM and would
| always call us into the room any time he was doing one of
| his crazy experiments on TV. I agree his stuff is very
| 'sampleable'
|
| Edit: Just watched the video, it's actually a gold mine
| for hip hop lol. Just play this in the background and
| scrub around his videos -
| https://www.youtube.com/watch?v=JVISRjhXzzM
|
| good thing it's friday (may need to fix volume) -
| http://www.youtubemultiplier.com/6095af3ba32b6-jsm-on-
| beats-...)
| filoeleven wrote:
| Oh that simultaneous site is neat! Doesn't work for me on
| iOS but what a great idea. I've been using two separate
| devices for that kind of thing (mostly confirming mashups
| that I will likely never follow through with, but it's
| still fun to do).
|
| Looks like you know more than me about how our brains
| process audio. I was running on the assumption that some
| kind of frequency analysis made it to our higher
| processing centers, is that not the case? Given that what
| we hear all the time is incredibly chaotic (multiple
| pitches that we hear as chords, lyrics vs the rest of the
| music, focusing on one person speaking, etc) I thought we
| must at least be running some kind of internal spectrum
| analyzer and continuously comparing new input to previous
| averages or something.
|
| There almost has to be a clock-like reference construct
| somewhere, right? The ability of some people to perceive
| perfect pitch points to it IMO.
| humaniania wrote:
| Are there AI projects working on mapping bird song into possible
| meanings to figure out a language?
| grawprog wrote:
| Those are intersting. They remind me of the sonographs we
| collected of bat echolocation calls when we were doing bat
| surveys with anabat detectors. Just by the shape of the calls you
| could narrow the bat down to a likely species and determine
| whether it was just flying around, actively hunting or about to
| eat a hapless insect.
|
| It was a pretty awesome device.
| klyrs wrote:
| > I don't know if it's a feature or a defect of the instrument.
|
| It's a feature
|
| https://monoskop.org/images/a/af/Gough_C_2007_The_violin_Chl...
| birdbrain wrote:
| I don't want to detract from the images, or the work that went
| into this, but, er, there are a _lot_ of types of birds. Just
| among passerines (songbirds), we 're talking over 6,000 species.
|
| So any sweeping statement like "birds don't seem to bother to
| create a complex multi-layered harmonics pattern" is practically
| guaranteed to be wrong. And so it is. Lots and lots of birds sing
| incredibly harmonically complex songs. Browse any of these
| (https://www.remoteenvironmentalassessmentlaboratory.com/expl...)
| if you're interested - it's a tiny sample of birds, and many,
| many of them do in fact have harmonically complex songs.
| throwamon wrote:
| For a moment I thought they would hypothesize that the patterns
| might be an actual "rendering" of what the birds were looking at,
| especially when I saw the 7th image which looks remarkably
| similar to a rodent.
|
| Apparently I'm pretty far off, but just this idea of animals
| communicating images with sound waves was something I'd otherwise
| never have.
| kurthr wrote:
| What if groups/species of birds had "collective synesthesia"?
|
| Some people see colors or feel tastes... and it doesn't seem
| that unlikely that there would be selection pressure for parts
| of the bird brain to connect their spatial awareness to their
| auditory system and then songs. There could be a nice feedback
| loop that their own songs would strike similar experiences for
| themselves (if they hear themselves similar to others).
|
| Of course we know that bats have this type of neural connection
| in echolocation and dolphins/whales may even using it to
| communicate in similar ways with their songs.
| mattkrause wrote:
| They kinda do!
|
| If you place migratory birds in a big round cage, they show
| 'Zugunruhe[0]', or migratory restlessness: they jump and
| flutter in the direction that they would be otherwise be
| migrating if they were out in the wild. Rotating the magnetic
| field (e.g., by putting magnets around the aviary) also
| rotates the direction of their Zugunruhe.
|
| No one totally understands how this works, but the magnetic
| information is thought to be 'overlaid' on other sensory
| information. One candidate pathway involves a light-dependent
| pathway in the retina. When a cryptochrome absorbs light, it
| generates radical pairs that affect how visual information is
| perceived[1]. This could give the birds something like HUD
| which displays magnetic field lines on top of the visual
| scene. Consistent with this idea, birds can only orient to
| magnetic fields under certain colors of light, with the color
| varying a bit from bird to bird[2]. It's almost as if the
| colored light washes out the HUD.
|
| There's another parallel pathway involving bits of magnetite
| in the beak[3,4]. These signals flow through the trigeminal
| nerve, which carries a lot of different signals; it would not
| be impossible for this to manifest as "pressure", as it
| carries touch/somatosensory information in many animals.
|
| [0] Ethologists love German and this word captures my
| lockdown feeling so very well. [1] https://www.sciencedirect.
| com/science/article/pii/S000634950... [2]
| https://www.nature.com/articles/364525a0 [3] https://www.scie
| ncedirect.com/science/article/pii/S000634950... [4] https://r
| oyalsocietypublishing.org/doi/10.1098/rspb.2009.005...
| akomtu wrote:
| I remember that "cymascope" experiment that used a dolphin's
| sound as input. Turned out the water surface had an image
| (after lots of noise deblurring) of a human the dolphin just
| seen. This means the organ that decodes sound is a simple
| membrane with water. How dolphins encode images into sound is
| a separate question.
| plutonorm wrote:
| I don't remember this but would extremely interested to see
| it. Any link?
| akomtu wrote:
| It was one of John Stuart Reid presentations.
| EamonnMR wrote:
| Since dolphins also 'see' with sonar, using the sonar
| response inflection of an object to refer to that object is
| sort of like an onomatopoeia.
| plutonorm wrote:
| I heard a crazy theory that this is how dolphins communicate.
| As they perceive using sound and are able to produce sound,
| perhaps they project the sound of the thing they want to talk
| about. It would be the same as a human being able to shine any
| image we like onto a wall to communicate. Can they recreate the
| echo of a fish with high enough fidelity that it's recognisable
| to another dolphin?
| jerrre wrote:
| Interesting train of thought.
|
| Perhaps it's good to know that the x axis (from left to right)
| is temporal. So for someone/something to translate this to an
| image with some special sense would also necessitate some
| memory part.
|
| With a big fantasy you could continue your hypothesis by
| comparing it to describing an object you see with words by
| telling the height of the outline from left to right.
| gbh444g wrote:
| I wanted to add that the nature of those thin horizontal layers
| and the patterns they form is similar to diffraction. A laser
| beam passing thru a thin slit forms a pattern with the sinc-wave
| distribution of intensity, and so is FFT of a rectangular window
| used in these spectrograms makes a sinc-wave shape that
| "diffracts" the "true" sound frequency.
| topspin wrote:
| It makes sense to me that bird song would have few harmonics.
| Although we may appreciate the beauty of bird song they don't
| sing for aesthetics. They are signaling. Concentrating energy
| into a narrow band delivers greater range for the same energy
| than harmonically rich signals. We do likewise with
| electromagnetic communication.
| crazygringo wrote:
| I think the explanation is even simpler.
|
| For a loud, high-pitched sound produced from a tiny object like
| a bird, is it even physically possible to have the loud
| resonances needed for overtones and timbre? I think it's just
| physics.
|
| Whales are "signaling" over huge distances too but have plenty
| of overtones, since that's what low frequencies in huge
| cavities produce.
|
| I'm not sure the dichotomy between "aesthetics" and "signaling"
| you suggest actually exists. A peacock's plumage is certainly
| aesthetics but also certainly signaling. And what is a
| birdsong's _melody_ if not aesthetics?
| periheli0n wrote:
| When a bird sings to attract a mating partner, competing
| against other birds, does it not sing for aesthetics?
|
| Also, couldn't harmonics be used to improve decoding in noisy
| environments? Spreading the signal over a wide band is not
| unheard of in man-made electromagnetic communication either.
| karmakaze wrote:
| When using spread-spectrum transmission it would be
| counterproductive to utilize harmonics. Non-sinusoidal noise
| at frequency F would pollute frequencies k*F. Also the
| transmission band is likely less than an octave.
| darig wrote:
| Signal strength is the aesthetic.
|
| If you were a bird, you'd spend so much time trying to change
| what you were that you'd forget to eat your worms and die.
| enchiridion wrote:
| I just had two thought considering this:
|
| 1. Do we appreciate bird songs because they indicate a resource
| rich/hospitable environment?
|
| 2. Do birds hear the entire range of the song, or just pick up
| specific bands?
| DoingIsLearning wrote:
| Dupe: https://news.ycombinator.com/item?id=27030171
| algui91 wrote:
| Ups, I though if some dup is detected I would be warned before
| submitting. Will remove it.
|
| Thanks!
|
| Edit: Seems I can not remove it by myself :-(
| neogodless wrote:
| No worries - the previous entry is not front page, and I
| missed it. Glad I caught it the second time around.
| luxuryballs wrote:
| Snek! https://soundshader.github.io/hss/gallery/bird/3.png
| kazinator wrote:
| > _However it would be a mistake to to call flute sound simple:
| as you see, every level has its own regular pattern that can't be
| recreated with a simple mix of sinusoidal tones._
|
| The resonance of the flute's air chamber is driven by the noise
| of forced air stream, which is why it contains high frequencies
| at all. Of course you can't recreate the flute sound just with
| some periodic sinusoidals, because the noise component has to be
| present. The noise is complex and is itself filtered by the
| flute's chamber, in a different way depending on which valves are
| closed. You can play a recognizeable scale on a flute without
| getting a tone out of it, just using air noise, the same way you
| can produce a musical tune using chhhh sounds out your mouth.
| Those notes, or something like them, are still there in the
| background when a tone is being produced. There is no flute tone
| without them.
| debbiedowner wrote:
| HSV color scheme looks beautiful, but since it doesn't seem to
| have perceptually uniform color change we won't see it used in
| papers much :(
|
| I think the rule for audio papers is linear change in color
| according to energy?
|
| So this rep may lead us to hallucinate our conclusions?
| slver wrote:
| I choose to imagine they're API endpoints communicating lists of
| entities with similar data causing the patterns.
| wombatmobile wrote:
| Um, I'd like to be able to parse this article. but I don't know
| what it is saying. Can anyone explain the gist of it to me in
| simple terms?
|
| What does this mean?
|
| "These sonograms are remarkably different from other sounds, as
| if birds "draw" with sound something that's flying backwards in
| time."
| usrbin wrote:
| Audio person here. I found the post fascinating, but I wish
| they did more to explain what they were talking about to a
| layperson.
|
| Basically, all sounds that you hear are composed of many
| layered sine waves of different frequencies and intensities.
| The graphs in the post are spectrograms, which graph those
| frequencies over time. The Y axis represents pitch, the X axis
| represents time, and the brightness at any given point
| represents how loud that particular frequency was at that
| particular time.
|
| Most sounds, even seemingly simple ones, look very complex on a
| sonogram, like a smudged pen stroke. The images of different
| instruments below demonstrate this; these are all very complex
| sounds, even though we only hear it as a single note being
| played. The voice one is one of my favorites, because it shows
| just how weird and complicated everyday sounds can get.
|
| But bird songs are different; on a sonogram, they appear as a
| single line. The complexity of the bird songs here comes from
| the fact that they're taking a single sine wave and changing
| the pitch over time. Where most sounds look like a complex mix
| of smudged paint strokes, bird songs look like a single,
| precise, bouncing stroke.
| klyrs wrote:
| That's really interesting... I wonder if it has something to
| do with birds have such small resonating chambers, so I
| looked for bigger birds. Apparently, emus make several calls
| that have interesting harmonics.
|
| https://www.xeno-canto.org/species/Dromaius-
| novaehollandiae?...
| J253 wrote:
| > on a sonogram, they appear as a single line.
|
| Which is akin to dragging a single finger across different
| piano keys. Only a single frequency, or note, played at a
| time. This is common among songbirds.
|
| Contrast that with the sound of a crow. The sonogram is much
| more broadband in signature. This is akin to mashing a bunch
| of keys on a piano all at the same time. Many frequencies
| present at simultaneously.
| wombatmobile wrote:
| I'd like to see fMRI of the listening birds' brains.
|
| Crows, in the morning, seem to be broadcasting work gang
| related information, organising their crew to go and
| harvest certain regions, then report back on the yield.
|
| If songbirds are courting, and hence broadcasting different
| information, for different purposes, I wonder if some
| generalisable differences might be apparent in the
| receiving birds brains.
| bradford wrote:
| > Which is akin to dragging a single finger across
| different piano keys. Only a single frequency, or note,
| played at a time.
|
| I think there's a key difference.
|
| Assuming this is the spectrogram of single note being
| played on the Piano
| (https://soundshader.github.io/hss/gallery/piano/2.jpg)
| (which I can't be certain of, since the audio sample wasn't
| provided). Seems like a single piano note fires on multiple
| frequencies, and our ear 'aggregates' them so we hear it as
| a single note.
|
| Songbird belts out a single frequency at each point in
| time. We still hear a single note but there's nothing to
| aggregate.
|
| At least that's my interpretation of the parent comments.
| Again, can't be sure.
| wombatmobile wrote:
| I wonder what information properties can be inferred from the
| characteristics of the avian audio signal.
|
| Are birds sending specific data packets eg weather, food
| prospecting geocoordinates? Or are they entertainers like
| Frank Sinatra or Dolly Parton?
|
| And could we decipher the language by studying data in
| context eg food hunts, mating rituals, predator warnings?
|
| What might Claude Shannon make of these spectrograms?
| Xophmeister wrote:
| So this would be a good example of a pure(ish) sine wave
| produced naturally, albeit modulating pitch over time? That's
| pretty rare, I believe.
| noxToken wrote:
| Andrew Huang does a good job of explaining harmonics and
| overtones[0]. You only need to watch until about the 4 minute
| mark (from the timestamp) to get an explanation of harmonics
| and what the sonograms represent.
|
| The short of it is that most natural sounds product a root tone
| plus a varying amount of related tones above it. Our ears hear
| the root tone, and the other tones above it are what give the
| sound its uniqueness. That's why a guitar, a clarinet and 3
| singers can produce the same note while sounding distinct.
|
| Birds seem to produce a natural sound without a lot of the
| related tones above it. Their sound is, relatively speaking,
| much purer than most other natural sounds. That's very unique.
|
| [0]: https://youtu.be/Wx_kugSemfY?t=95
| temporalparts wrote:
| Slight related tangent: For all those interested in birding, I
| highly recommend the BirdNet app available on Android and iOS!
| You can record and send audio data, and it will try to classify
| the bird for you based on the recording.
|
| In the process of recording, it will show you the bird's
| spectrograms, which is really cool!
| algui91 wrote:
| That's really cool! trying it out now. thanks for the
| recommendation.
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