Sound insulating adjoining wall between semi d's

I have a chance soon to sound insulate my bedroom wall between us & our inconsiderate neighbours, so does anyone know if this can be done without taking a huge amount of space away from your floor area by beefing up the wall?

Is there a good material that can be used that will deaden the sound without being too think?

I'll be putting the bedroom wardrobes over it, so it won't be getting a nice plastered finish apart from the area that the bed will be against, unless I cover that with a large headboard