I live in a flat in panel house. This type of building is typical to former soviet countries and it looks like this:
The whole building is made from concrete panels which are welded together using the armatures. This means that the sound travels between flats/rooms easily.
Now the problem is I have three direct neighbors one next to me, one above and one diagonally above. One of them is really noisy. By the sound I would judge they are moving furniture, using anvil and playing bowling. Today it started at 4AM.
I would like to reason with the noisy neighbor but I don't know which one of them is causing that as it is hard to pinpoint the exact source of the sound due to acoustics in the room.
What would be the best way to find the source of the noise?