There were not "screams" just one and that is an important distinction. Waking up to one you would listen question what you heard and keep listening. That is why Nara couldn't justify calling police , she didn't hear fighting or screaming she heard one scream running then nothing. Nara said she hadn't heard a scream like that before, which made it stand out. As far as the noise can you hear a dog barking coming from the valley in Piazza Grimana or hear people talking outside on the cottage patio? No absolutely not the trees ,buildings , traffic noise and distance prevent that, but guess what you can hear both these sounds standing in the upper parking lot facing the cottage.It is the nature of the landscape with no obstruction, If these sounds carry up to the parking lot then a loud scream would certainly be heard through a closed window above.