Yeah man, OpenAL, tis free, cross platform and it works. But don't expect it to hold your hand

Fmod has pascal headers floating around, at least for the fmod 3 api. free for non-commercial but very pricey, even for a hobby licence.

Oh and there's BASS of course : http://www.un4seen.com/

comes with pascal headers, free for non commercial use, but far cheaper than fmod, the shareware licence is quite reasonable if you're looking to profit from your passion.

Audorra seems like a good choice on paper, but I've not used it so can't comment on implementation, however the developer writes excellent code, I know that much.