Using my Roll20 Audio Master script and my customizable roll listener script should get you what you want. You could also add the roll20AM command(s) to the end of your initiative macro instead of using the CRL script if you have access to the macro code. Edit, I should note, the one_click install version of roll20am is currently bugged, use the latest version from my branch of the repository tho, and it should work fine tho.