While this house is rather large and rather spread out, it is also remarkably easy to hear things in it… from certain places.  Upstairs, sound does not travel in between the north end and the center (never mind the south end) despite the short distance: this makes sense given the bent hallways and multiple walls.  It makes even more sense when one remembers that one of the walls in question was formerly an exterior wall containing a staircase.  On the other hand, in my room at the extreme north end on the second floor, I can hear the fire alarm above the washing machine located in the extreme south end in the basement.  Which doesn’t make sense right? 

Well, except that the basement going north is basically a long narrow box made of stone.  When it hits the north end it jogs around the old foundation wall (the same wall which is a former exterior wall on the second story), which would stop the sound, except…  The old hot air ducts for the forced air coal furnace are still in  place, but open at the bottom.  The sound is neatly funnelled into those and bounces on up to the second story quite neatly.

Now I suppose, that same alarm might not be audible in the center and south sections, despite being closer, since the hot air ducts are not in those areas.  I ought to experiment.

Useful to know the fire alarm will wake one up though.  Granted it took awhile since it was just a flat battery and not the full-on shriek.