Wherever I have lived in apartments, beneath someone who has installed a timber floor, I have encountered the same noise:
It’s weird – something like a jar of marbles being dropped on the floor with its contents left to roll where they may,
At first I thought it was strange that the people upstairs had marbles in a jar. And that they were so careless with them.
The second time, in a different flat, I wondered if the people who used to live upstairs from us had moved when we did. Or that the new people were also members of a cult that worshipped a jar full of marbles. Or there was a club that we hadn’t been invited to join because marble jar ownership was a prerequisite.
On our third apartment when I heard the noise, I thought poltergeist! Then I saw this video. Suddenly everything makes sense.