Created by Alexander Zolotov, and based based on the unique Russian synthesizer ANS by Evgeny Murzin, PhonoPaper is a format of graphical representation of the sound (music, human voice, etc.); in other words, it is the 2D audio barcode (by analogy with the QR-code). The app, available for both iOS and Android is also a real-time PhonoPaper-code reader (using the camera).
PhonoPaper app allows code generator (sound to image converter) so the messages in print format can be re-read by the software. PhonoPaper-code is analogue, so it is not so sensitive to different types of the image distortion (bad camera, dark picture, wrinkled paper, etc.). Likewise, PhonoPaper-code can be drawn by hand (paper version of the Virtual ANS synth). You can leave coded voice messages (or pieces of music) on the billboards, posters, postcards, goods. You can also create audio labels for phono records or leave audio examples in textbooks, secret messages, art-experiments and of course learn the basics of the spectral music.
h/t Jeremy Rotsztain