Yesterday I was right next to my living room closet, which is about 2 feet away from my neighbours living room closet, since we live on the same floor. Let me tell you that I can hear everything on her side and she can also hear everything on my side when we are this close to one another.
So, unexpectedly, I made a very loud fart, and about 2 seconds later I heard my neighbour fooling around in her closet, 2 feet away.
You guessed it, she surely heard my very loud fart