Well, my sound implementation was not a great success. Some of it worked, some didn't, despite close monitoring on debug that the right things were being called with the right parameters. Specifically, setLoop didn't seem to work, nor did pause nor autopause. Most of the problems were with the background music and ambience sounds. The simple sound effects were fine.
I note a lot of such mysterious problems on Stackoverflow, and I may change policy here.
Also, I think it should have been a class rather than a method, and I'll re-write it like that. I may also have to use the MediaPlayer for longer music and the Soundpool just for immediate sound effects. We'll see. MediaPlayer is facility-rich, but seems rather complex to use.