If you are rolling the macro from the sheet you probably won't be able to do it, unless the sheet allows you to modify the entire output of your rolls (add a line to the macro). If you are using a token macro or personal macro to make the rolls, I would use the Roll20 Audio Master script by Scott C. You can get it via the Script Library under Campaign > Settings > API Scripts. An example of how I use it: I will find a sound effect I like on Fanburst, add it to my game and name it something simple like "SwordAttack". I then would add this to the end of an attack macro: !roll20AM --play|SwordAttack The Roll20 Audio Master script will then play the sound of my sword swinging.