Allan Friswell's comment (scroll down) on this video for "O Superman" for Laurie Anderson contends:
The UK nuclear power stations of the 80s had that "ha" sound on continuously 24/7. Apparently it got so you stopped hearing it, and only when it STOPPED did you know there was an emergency. Apparently you heard the silence quicker than if it were an audible alarm.
(the song features a soft "ha" looping continuously in the background). This has some serious poetic heft, so I want to believe it, but I also don't trust it for the same reasons.
Can anyone confirm or deny?