I'm using natty. I'm using classic. I use raw xterms (the latest build, 270, in fact). I've done
xset b 100 pactl upload-sample /usr/share/sounds/ubuntu/stereo/message.ogg bell.ogg
But I want something more fine grained than this: I want to say "if the bell originated in some particular pseudoterminal make a particular sound, but if it originated in some other particular pseudoterminal, generate some other sound"