What's the max number of "sounds" 3GS can play back at the same time assuming a decent quality sample, eg 16 bit, 41khz+ ?
Or, if nobody knows, how would I best go about testing this out?
You can test this by downloading Audacity, a free sound editor, and importing an audio file. You can set the frequency of the file and then export it. Then you can use the exported files for testing in Unity.