When we moved into our last semi detached house in the UK we soon found out that the kid next door liked his audio player on full volume when his mum was out...The walls were vibrating All freaking morning.
I went to my trade supplier and bought 6 sheets of plaster board..
I removed the skirting boards (luckily we had no coving) and stuck the first layer of boards with adhesive onto the party wall.. I let that stick,then put another plaster board layer over that..Tape and jointed the seams and redecorated..Glued skirting back on. Reduced the noise by 75%..
If you want more noise reduction..Use this stuff instead..
http://www.soundreduction.co.uk/Prod...ard-For-Walls/
I recommend you get this done ASAP..You`ll be glad you did and just think.. You can scream as much as you like without them hearing!!
Win win.