Why?

Why does the apartment upstairs from us constantly emit a sound like a laughing sheep with a basso profundo? Seriously; I'd love an answer to this question. I have a feeling that it may be the water pipes, because I hear it most often from the alleged security of my shower. Still, it didn't start until just a few weeks ago, so I can't imagine what they've been doing upstairs to put the pipes in such a passion that they need to bellow their discomfort like dehydrated cows.

As another note about our building:

After locking ourselves out the other night (it was bound to happen, and of course the night just after we had keys cut and forgot to hand them to our friends down the road!), I realised that conversations and general noise in the flats travel VERY well into the main corridor. And I do mean, VERY, incredibly, disconcertingly well. I could clearly hear the slightly winging conversations our neighbours were having about some friends of theirs and running out to get booze. I could also hear the family below us having dinner with their petulant colicy baby. This lack of soundproofing worries me. How many of our conversations must our neighbours hear!?

In the meantime, I will try not to worry about advertising all of my activities to the neighbours and get back to some good old-fashioned reading. I have a historical detective novel to sink my teeth into and it's begging for some more quality time.