Water flowing through pipes in walls is too loud, how to dampen the sound.?

I live in an apartment building with one apartment above mine. Their bathroom drain pipes must be housed in one of bedroom walls. Everytime they use the shower, sink or flush the toilet, I hear a loud surge of water as it splashes down the pipes. A 15 minute shower sounds like they're in the room with me, riding white water rapids. It's so loud and annoying. Is there anything I (or maybe my neighbors) can do to soften the sound. I suspect the walls were poorly insulated and the plumbing wasn't thoughtfully or properly installed to begin with. We all rent, so tearing down walls is not an option.