Sound sets can be added by creating a new folder in the Sounds folder. Files are:

    EX_POP_0.wav
    EX_POP_(number).wav
    EX_POP_SUB.wav

To get 16 sounds playing, name your files EX_POP_0.wav through EX_POP_15.wav.

The script randomly plays a numbered exhaust sound. Sub always plays. 
