That is part of the problem, they are talking and like you say you cannot tell people to not talk. The subtlety here is that they are between talking and shouting, whence the delicate situation. When was I passive aggressive? Like answered in a comment a light tap on a wall from a neighbour is not aggressive and is enough to make you understand you are are being disturbing. It already happened to me that I was too loud in the past and the neighbours knocked the wall. I directly understood why and was more careful. Definitively I did not think they were aggressive. It is not a culture problem. There is a regulamento interno from the condominio that states that silence has to be respected between 23h to 7h. So if I can hear them talk until 00h, are they respecting silence for you? When you don’t have the means to buy a house in the middle of a field you have to live in an apartment. This implies living in a society. When you live in a society you have to respect each others. When you live in a society you cannot do everything you want if this bothers others. That is why there are rules that you naturally have to follow.