There’s a whole lot of work being done on monitoring the health and
status of systems using differing patterns of background sound. Perhaps
your server farm sounds like a rain forest, and a cricket chirps every time
someone portscans you.
It turns out I have one of these set up for free. I run continuous builds
for our books in production on my office G5, and the G5 fans are very
responsive to processor load. So whenever the build system decides to
rebuild a book (because an author has checked in changes), the fans kick
in, and I can wander over and see what’s cooking. It’s
surprisingly useful feedback.