The problem with Perl/SDL, is that as far as I know, you can only play existing sound files. In other words, you can't stream and you can't generate your own samples on the fly. That's probably great if you want to use pregenerated samples in games, but if you want to do your own "live" effects etc it's pretty useless.

update: after some browsing, it seems that SDL itself should be reasonably good for this kind of thing, but the Perl API has abstracted away the required low-level hooks.