Posting a note through my downstairs neighbours door asking her if she could turn her telly down slightly? 
I can hear it under my bedroom every night and it's not mega loud, but I can hear it. God knows what it is, but there's screaming and laughing and I've resorted to ear plugs, which aren't comfortable. It was still going at 3.30 the other morning when I woke for the toilet. I'm worried I'm just becoming irritable as I get older and can't expect to fall asleep in 100% silence?
We say hello in passing, by that's it.