The air handler above my office just shut off (hopefully intentionally, and not because it's broken), and it's shocking to hear the difference between the constant din of rushing air and the quiet.
Of course, I can still hear the women over in advertising clucking away about their offspring. At least I can shut my office door to fix that.
Edit: Dammit, that didn't last long. The infernal whirring is back. I'm sure it's resulted in some long-term hearing loss, brain damage, or both.