Ugh. I lived in a situation like this for about 3 years, it was utter hell. It was a NYC (Queens) co-op, pre-war, so there was no insulation at all between the (hardwood) floors. People upstairs (in a studio apartment no less, there wasn't even a bedroom, so there was no escaping any of this) had a toddler that they allowed to constantly run back & forth all day and night and also to play with hard wooden toys and also, in a particularly selfish and clueless move, a KEYBOARD laid on the bare floor (oh yeah and these neighbors refused to put a stitch of rug or carpeting down). The plaster would literally fall off of my walls and ceilings. This would basically start at about 6:30/7 AM and end around 10/10:30 PM. I was both physically and emotionally exhausted all the time. The pounding would start, as would the escalating pounding in my heart. I could actually feel my blood pressure rising. The attitude of these people was always, "well, it's a child, so too bad". The only relief came when these people finally moved out. Anyway, I am so sorry to hear that you are experiencing a similar problem. I think the only thing you really can do is talk to your neighbors about it. I hope they are more reasonable than mine were.