Thank you, that was the problem. I have no earthly idea how that could have been muted. Must have hit some bizarre keyboard shortcut or something. Thanks again!

I was in the middle of development using ZeroBrane Studio, on linux (opensuse TW). Been working all day. Made some minor tweak, totally unrelated to sound, and now whenever I execute any love program, whether from command line or through the IDE, no sounds play at all. So weird. I rebooted, uninstal...