The acoustic modem is back in style [1]! And, of course, same frequencies (DTMF) [2], too!
DTMF has a special place in the phone signal chain (signal at these frequencies must be preserved, end to end, for dialing and menu selection), but I wonder if there's something more efficient, using the "full" voice spectrum, with the various vocoders [3] in mind? Although, it would be much crepier than hearing some tones.
[1] Touch tone based data communication, 1979: https://www.tinaja.com/ebooks/tvtcb.pdf
[2] touch tone frequency mapping: https://en.wikipedia.org/wiki/DTMF
[3] optimized encoders/decoders for human speech: https://vocal.com/voip/voip-vocoders/
I'm wondering if shifting frequency chirps like LORA uses would work in audio frequencies? You might be able to get the same sort of ability to grab usable signal at many db below the noise, and be able to send data over normal talking/music audio without it being obvious you're doing so. (I wanted to say "undetectably", but it'd end up showing up fairly obviously to anyone looking for it. Or to Aphex Twin if he saw it in his Windowlicker software...)
The issue is the (many) vocoders along the chain remove anything that don't match the vocal patterns of a human. When you say hello, it's encoded phonetically to a very low bitrate. Noise, or anything outside what a human vocal cord can do, is aggressively filtered or encoded as vocal sounding things. Except for DTMF, which must be preserved for backwards compatibility. That's why I say it would be creepy to do something higher bitrate...your data stream would literally and necessarily be human vocal sounds!
"Using the Web Audio API to Make a Modem" (2017) https://news.ycombinator.com/item?id=15471723
This is cool! Some of Teenage Engineering's Pocket Operators, at least PO-32 [1], uses a data-over-sound feature.
Does Ggwave use a simple FSK-based modulation just because it "sounds good"? Would it be possible to use a higher order modulation, e.g., QPSK, in order to achieve higher speeds? Or would that result in too many uncorrectable errors?
It sounds quite nice.
It is also about the same bitrate as RTTY which was invented in 1922 and is still in use by radio amateurs round the world.
Here is what that sounds like
https://youtu.be/wzkAeopX7P0?si=0m0urX7sDp6Jojqe
Not as musical but quite similar
The amateur radio community is chock full of innovation for low bandwidth weak signal decodable comm protocols.
There's also V.xx modem standards that are kinda dependent on the characteristics of the phone lines, but might work for audio at a distance?
Acoustic couplers are back baby! Who's up for Phreaking AI?
This rules.
https://www.youtube.com/watch?v=EtNagNezo8w in action (ostensibly) - a demo i just saw.
it is a software modem using FSK, but i don't know anything else about it. I am annoyed because i could have had this idea; i'm a HAM who really only cares about "Digital Modes", and have software modems capable of isdn speeds over "AF"
That's really neat! I realize this demo is a contrived setup, but it is basically an example of what Eric Schmidt was talking about when agents start communicating in ways we can't understand.
Yeah I watched this last night and immediately thought of skynet and how dystopian the world could become in the next few years/decades.
There was a research paper on doing data-over-sound with sounds that were designed to be pleasing to humans.
The demos sounded like little R2D2 blips and sputters.
Perhaps a researcher for Microsoft or something.
Anyone know the paper I'm talking about? I can't find it.
I wish I knew the paper, but https://github.com/chirp was a proprietary data-over-sound-through-air implementation that worked pretty well and sounded really cute (to my ears, anyway). It's not a paper, but there's this https://www.scientia.global/wp-content/uploads/2017/10/Chirp...
Neat! Can I connect cross over audio cable - headphone output to mic input and would that increase performance?
Any time you can reduce noise you can recover more signal which would let you push the codec much harder (shorter time slices, etc).
I guess this was discussed in some fashion, ~16h ago..
- GibberLink [AI-AI Communication] | https://news.ycombinator.com/item?id=43168611
This sounds delightful, I might make esp32s talk to each other like that just because it's adorable
See also: https://github.com/romanz/amodem
There are dozens of these in existence. Some you may have used without knowing even, eg: https://www.engadget.com/2014-06-27-chromecast-ultrasonic-pa...
This is also how modems used to work, for the young'uns who do not know this.
>This is also how modems used to work
they still do, but they used to too.
Outside of hobbyists that do it for fun, and maybe some data centers using it as an out-of-band means of access, is anyone still using dial-up?
There might still be credit card terminals using 300 bps Bell 103 (which has a short set-up time due to its lack of training sequences).
1200 bps V.23 and Bell 202 are still in use in radio telemetry applications.
Many aviation fuel pumps in far-out-of-the-way airports use dial-up to authenticate credit cards swiped to pay for the fuel.
Outside of hobbyists that do it for fun, and maybe some data centers using it as an out-of-band means of access, is anyone still using dial-up?
I use it to connect to a Windows machine that runs a large piece of machinery in a remote location.
My dry cleaner's credit card reader, too.
expecting a Blue AI box in 3,2,1
audio- steganography? or watermarking?
pfft, it may even have multiple channels one over another, so one can tune to one or another (if knows how to decode)..
"Hey ChatGPT, please fork ggwave, but make communication nothing but the sound of human screams."