Tuneic
Tuneic[1] is the secret audio language in Tunic. It is a musical cipher hidden throughout the game but never acknowledged. It is present in sound effects and the soundtrack itself. One phoneme in Tuneic is one pentatonic arpeggio. In this way, entities secretly "speak," and certain music tracks have "lyrics."
The Rosetta Stone for Tuneic is found in a spectrogram created by a.mp3, the "reward" for solving the Glyph Tower puzzle.
Google Document
Tuneic (Sound Puzzle Mappings)
Spectrogram Secrets
a.mp3 from doyoufeartheeyesofthefarshore.co
Trunic translation: "We are the(e) eyes of the far shore"
Dark Passage behind the Old House
Image: The doodle of fox from page 52 of the instruction manual.