ChromaDoze

Generates noise with a custom colour profile. It is intended to be used as a
sleep sound generator. It provides rapid feedback to adjustments in the
spectrum, and is designed to minimize CPU usage in the steady state.

It works by running shaped white noise through an Inverse Discrete Cosine
Transform, generating a few megabytes of distinct audio blocks. The steady-state
behavior selects blocks at random, and smoothly crossfades between them