This function creates a new audio bus and returns an AudioBus Struct through which you can access and modify it.
NOTE A user-created audio bus will be garbage collected when it's unreferenced and any linked emitters are destroyed, and as such there is no "destroy" or "free" function for audio buses.
audio_bus_create();
emitter1 = audio_emitter_create();
emitter1_bus = audio_bus_create();
audio_emitter_bus(emitter1, emitter1_bus);
audio_play_sound_on(emitter1, snd_Ambience, true, 100);
The above code first creates a new audio emitter and a new audio bus. It then assigns the emitter to the bus, and plays a sound on the emitter.
The sound will have any effects from emitter1_bus applied first and then the ones fromaudio_bus_main.