I actually sometimes associate words with sound and color - it makes me wonder why we are still limiting ourselves only visual feedback. I vaguely remember somebody posting a lisp-y emacs-y setup of a synth coding environment of sorts that looked like heaven to me. (You'd quickly iterate on code with transforms that would shift the sound playing at all times and the colors would POP at you) It also makes me wonder ho…
Changing tone based on depth could be pretty interesting, as could tones representing things like unused variables.
Based on your preferences, you could also do things like have the noise grow unpleasant if you do something you shouldn't (e.g., reuse a variable name, write an impure function, etc.).