An an item that creates an Acoustic Space field around it.
Would give the ability to change the "interior" ambient and weather sounds of a settlement structure to the interior sounds.
The houses of Sanctuary have this feature. The acoustic space within these buildings is an interior one despite them being part of an exterior cell.
I don't know if it is already an object within the creation kit.
Might work like a light or sound source.
Or it simply just creates a space of whatever shape(5x5x5 units,10x10x10 units, 20x20x20 units, ...).
The item would be placed via the Workshop menu and would muffle the ambient weather sounds(original or mod--> NAC X).
So when you are in your massive concrete, brick structure with comfy fire place and warm wood panels a storm would no longer make it sound like you are just on an open field.