Sorry for the late response. I've so many things to do today.
Our walls are not thin. We live in terraced housing and our row of houses are rather old build. Proper solid thick walls.
Family consist of Mum, 4 teenagers (2 x girls 2 x boys) and I presume, Partner of Mum who stays a few nights of the week.
Noise consists of 4 teenagers coming and going through the evening until early hours of the morning. Its the summer holidays now, and the noise extends until well after midnight and into 4 am.
Hammering flooring/walls (I'm unsure which) after 11pm on afew occasions was/is soothing to hear 
Argueing, shreiking, fighting, noisy gatherings. All from the late evning until early hours.
Most odd thing is that it seems as if there is only one set of keys between the family. Mum stays in most times, and its the 4 children who come and go more frequently. Everytime they come back home, they have to knock to be let back in. So its usually...kid arrives at door. (Its late by the way, kids are in bed, the street is queit, most of our neighbours have settled in for the night). Heavy knocking on the front door... Within he/she is banging on their front room window, not even having the common sense to realise that time needs to be given to allow someone to get from whichever room their in within the house, to the front door. Literally seconds after this, their back to hammering on the door again. Then its the letterbox. Then its shouting. (Remember, its dark, quiet). Sometimes a couple of kicks to the door is thrown in for good measure, a few more bangs on the door, before someone arrives to allow them in.. This is multiplied by four. Through the night. 
Our bedroom is to the front of the house. Its so shockingly loud.
DS room and our bedroom is adjacent to the noisy neighbours and DS suffers
alot.
DD sleeps on the other side of the house and last night we found DD awake in her room, lights on, early hours because the noise travelled from noisy neighbours house to her room.