In order to stop rain soaking in through the walls a narrow 15cm steel eave was added above a couple of windows at my place. It does the job, we no longer get any water entering the building. But, it is incredibly loud when it rains heavily. I suspect there are a couple of reasons for this: unlike a regular roof, there's nothing underneath to muffle the sound, no insulation or ceiling. Second, because it is free standing one end isn't anchored, just held up on occasional brackets. Lastly it may not actually be the direct raindrops that make it so loud, but larger drops from the same eave one floor above, so that the impact is much harder and louder than regular raindrops.
I was wondering if a foam or rubber could be glued to the under surface to muffle the sound? I've done a little searching, and most noise reduction methods seem to be focused on sky lights, or else putting a mesh above the roof to cut the speed of the drops. That might be a solution, but not as simple as gluing something underneath. But that's only my guess about what would help... Any other ideas?