message: Examples: TrebBoost_wComp_wApp: remove unneeded extern
diff: //classes from the main sketch that might be used here
  extern Tympan myTympan; //created in the main *.ino file
  extern State myState; //created in the main *.ino file
  -extern AudioSettings_F32 audio_settings; //created in the main *.ino file
  //functions in the main sketch that I want to call from here
  extern void incrementHighpassFilters(float);
  