Under the terms of the flat are they actually allowed hardwood floors?I think it is hardwood floors, but they've got rugs from the few times I've been up there. I'm not sure a white noise machine would cover up how loud it is - the other problem is there can be silence for hours, and then all of a sudden SLAM SLAM SLAM. I'll give it a go on my phone and see if I sleep better tonight - they're really at it right now!
My mums flat states in the leasehold not allowed even though she is ground floor. The guy she bought it off said he had hardwood flooring installed the freeholder found out and made them remove it!
So I woukd try and find out if that's the case as if it is the freeholder can make them change to carpet.