I had a couple of noisy neighbor situations. First there were these 2 girls that lived upstairs from me and they were really tiny (like maybe 100 pounds) but it always sounded like elephants stomping. My rommmate and I were on good terms with them and one day she asked one of the girls what was going on up there. Turns out they were doing their aerobics and tae bo tapes and that was the stomping. Although even their walking sounded really loud.
I lived in this apt for 3 years and the next guy that moved in upstairs was awful. I wasn't that we would hear him walking....he would turn his music up LOUD at like 2am and the bass would just come filtering down. We weren't on good terms with him though and we would sometimes take the broom and knock on the ceiling but it never worked. However, this fall a really nice girl moved in upstairs and I never knew she was there. I never heard anything--walking,music, talking, etc. But she would come down sometimes and ask if she was being too loud and I never even heard her.
Onto my LOVELY ex-next door neighbors. For 2 years these wonderful people moved there and we never had any trouble. Then this summer it all went down the tubes. The 2 guys that moved in were SO LOUD all the time. They would blast their music at all hours and have huge parties. They were so loud my dishes were shaking in my cabinets and the furniture was vibrating

Everyone in our building tried to handle it as mature adults but it kept going. So we started calling the non-emergency police number. And the cops would come and tell them to turn it down...it would last for like 15 minutes and then return. It was PURE HELL and we started complaining to our apartment manager (who when we first complained told us to call the cops) They eventually were evicted, but it figures that it was only a couple weeks before I moved out.