We live across the street from tornado sirens.
Every other Wednesday, they are tested for 2 or 3 minutes at noon.
It was something I'd forget and try to put Evelyn down for a nap and then they'd go off a few minutes later. I learned to remember pretty quickly.
If she's already been sleeping for a while, the noise doesn't even wake her.
If she's nursing, I just put my hand over her ear and we smile at each other.
(I should write posts all the time about how great ear protectors are.)