I have the same problem as you so I know exactly what you mean. Like you, there is a three year old kid running and jumping above, and her sibling about to join in! The couple removed all carpeting and had the floors sanded... Before they moved in, we did have a neighbour who went in for heavy metal so we were relieved when the occupants changed but the joy was of short duration. In fact, the occupants are much much worse They never seem to sleep, keep stomping around day and night, dropping things on the bare -or barely covered- floors, moving furniture, banging things around slamming doors, and the children cry (scream really) an awful lot. This is really depressing. We work during the day and come back to rest but there is just never any peace except when they go away, which alas is not often. Weekends are worse - because we don't have the work place to escape to! We could sell - but how do you sell a place which is so noisy????