I'd say I've been fairly lucky over the years to have considerate neighbors. I understand the reality of urban life, that we are all going to hear each other at some point. (As an aside, I always chuckle when I'm reading consumer hotel reviews and people complain about being able to hear footsteps above them or the TV from the next room.)
I believe some new people have moved into the apartment that has the garden next to mine. Last night, they were having a cookout -- probably no more than eight people, but they were so loud, communicating by yelling, like excited yelling, each trying to outyell the other that I finally went out there around 8:30 pm to ask them if they could hold it down just a bit. What prompted it is that I had my TV up to the highest volume and literally could not hear it.
I was shouting at the top of my lungs and they didn't hear or notice me... finally one guy did, never apologized, but shushed everyone temporarily which I knew would not last. The noise eventually built itself back up, and then around 11 pm, they start playing music on top of it. Yelling and loud music. I asked again and nothing, no response. I really considered calling the police but didn't.
So eventually around midnight, I closed the garden door and turned on the air conditioner which I didn't want to do, but it was my only choice to block the sound.
I kept thinking that I don't believe we were ever that rude when we were younger -- these were guys in their early 20s, but they were truly oblivious to the noise they made.
I may have told this story before, but when I lived on York Avenue, there was a party going on that shook the building, it was so loud. When I got up Sunday morning to go get the newspapers, it was stone silent in the building and I rarely, rarely do something like this, but I laid into their buzzer. Then I saw a popsicle stick on the floor, and I was able to wedge the popsicle stick into the buzzer so it was endless buzzing and happily walked out to get the papers and bagels. By the time I got back, the stick was gone, but I felt as if I had anonymously made my point, and it gave me great pleasure.