Sound is a good cue to problems. At Viaweb we had a big board of dials showing what was happening to our web servers. The hands were moved by little servomotors that made a slight noise when they turned. I couldn’t see the board from my desk, but I found that I could tell immediately, by the sound, when there was a problem with a server.
Interesting, the over-emphasis on the visual as a cue is a major weakness of so many interfaces and leads to overload
