Piston Collage noise
From Just Solve the File Format Problem
Piston Collage noise is one of the formats for sound clips used in creating songs with the Piston Collage / PxTone music creation program, alongside Piston Collage voice. (More general sound formats like WAV can also be used.)
A Piston Collage noise has 4 oscillators and is generally used for drums or sound effects.
Files start with bytes
50 54 4E 4F 49 53 45 2D, or "
PTNOISE-" in ASCII.