if you look at the beep example in the SDK, there is example code for playing multiple audio events at the same time. Some limitations with that, volume control doesn't work (you'll get 100% volume whether you want it or not), it only works on roku 2, and it will hard crash older roku boxes.
I had better luck just playing one sound at a time. Did this by prioritizing sounds to check what is playing, and if something with more priority is already playing, don't play the new sound.
good luck!
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