I wasn't sure what the overhead of creating the array was (I was looking to run this entirely in a script module, and so have no state to permanently store an array), so in the end I've defined case statements in a macro (all on one line), where each case returns an AudioClip. This seems to workaround it (when I import another AudioClip, I also add a case that returns it, and I just generate a random number to randomly get one).