I'm wondering if there is any protocol which would allow to encode data through audio in a human tolerable kind of way ?

An example would be the LTC protocol which is not at all human tolerable (my left ear remember) but it encode timecode information in an audio signal for synchronisation purposes.

The application could be to transmit an URL through a radio show or a podcast without having to click the description.

Of course it would require a dedicated decoder on the listener device (like for QR code which is mainly integrated in the device camera these days).


Another application would be to carry information along the signal like watermark do for a video.

  • 1
    What would be the benefit? Radio stations can already transmit a large amount of non-music data alongside the audio. DSL used to do something similar by using the analog audio bandwidth above that of the usable human voice range, using a splitter. That won't work for digital because of Nyquist/Shannon & because you can't lop the top off music like you can the human voice.
    – Tetsujin
    Apr 18, 2022 at 8:54
  • The idea wouldn't be to hide the audio signal encoding data. QR code are visible to the human eyes. The benefit would be that the audio would self contains the data. I'm not sure if there is industrial application to this but at least on an artistic point of view it could be nice to have a double content to an audio signal (one esthetic one and another informational one). Like QR code art. Apr 19, 2022 at 13:13
  • 1
    In some TV channels I hear a few tones right when the commercials begin. Is it DTMF? OTOH, just going with the question, QR code allow the transfer of information from one device (or medium) to another by optical means. In audio the equivalent could be, for example, your phone listening for a URL "played" on your car's radio... Is that what you mean?
    – Jahaziel
    Apr 20, 2022 at 0:16
  • @Jahaziel yes. Like a QR code I could accept a certain level of degradation. Apr 22, 2022 at 14:29
  • Would kind of be / is morse code, just even simpler, wouldn't it?! Furthermore you could always build a software that takes tone/tone area A for 'Black' and B (or a pause) for 'white' and simply transmits a standard qr code (whatever it contains) that way. But i guess you're asking for a standard with already existing ''decryption'' apps like common qr scanners for visual qr codes?! May 1, 2022 at 21:02

1 Answer 1


Dual-tone multi-frequency signaling (DTMF) seems to be the obvious answer, because it also has two dimensions (two sets of tones).

To make the tones more tolerable, you could move them to a lower frequency.

To transmit an URL you would need to furter encode your data, like e.g. with an evolved form of something like a BASE64 encoding.

However, while all this would work, it sounds quite involved and probably is not the solution to your actual problem anyway.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.