"Inst-foo" and "Voices-bar" will correspond to "FOO" and "BAR" difficulties respectively. You currently cannot have two difficulties use the special audio files without duplicating them under different names.
A helpful addition
A line in the .json file that itself determines which Inst and Voices files are used. That way, there can be multiple difficulties that use the audio files labeled with "ERECT" or "GODMODE" difficulty, for example, if need be.
What's currently there
"Inst-foo" and "Voices-bar" will correspond to "FOO" and "BAR" difficulties respectively. You currently cannot have two difficulties use the special audio files without duplicating them under different names.
A helpful addition
A line in the .json file that itself determines which Inst and Voices files are used. That way, there can be multiple difficulties that use the audio files labeled with "ERECT" or "GODMODE" difficulty, for example, if need be.