I live in a high rise in a major US metro (not NYC). A building across the way installed a new HVAC handler that whines at a relatively high pitch (think industrial shop vac) 24/7. One of my favorite parts of fall is being able to have the windows open and have lovely fresh air, but I can hardly hear myself think. And we're a good 100m away from the thing!

This is to say nothing of the traffic noise or garbage trucks or whatnot--but a building appliance? I thought surely that must be regulated, or at least controllable. It's unreal the lack of attention people pay to it.