I recently added Ruby as an embedded language in my sound editor
Snd, available at 

ftp://ccrma-ftp.stanford.edu/pub/Lisp/snd-5.tar.gz
http://www-ccrma.stanford.edu/software/snd/
http://sourceforge.net/projects/snd/

The underlying library of sound/audio stuff (sndlib) could be used
as a Ruby module, I assume, but I haven't tried that.  This is all
brand-new, still has gaps, etc.