How noisy is a metal roof in the rain?
I live in a log home with metal gable roofs.  They're made of metal panels, overlapped and screwed though with gaskets etc., but no insulation beneath them (there's an attic).  The metal roof does indeed add noticeable noise in a rainstorm, but we find it actually soothing.  It's sort of a soft drumming noise, except in the worst storms.  More surprisingly, we hear the panels clank and pop all day long, as the sun heats different sections of them.  Again, not a bothersome sound, but even after 6 months in the house, we still remark on it frequently.