I've just fitted a layer of polystyrene, wood batterns 2x2 with Rockwall infill and layer of acoustic plasterboard then plastered over. All sealed with soundproof sealant. Spoken word reduced through party wall but banging doors and wood wardrobe doors no difference. What else can I try?
There are two kinds of “sound control” problems: 1) air borne sounds, and 2) impact sounds.
1) Air borne sounds (talking, tv, etc.) is the easiest to control and it looks like you’ve solved that issue.
2) Impact sound (closing doors, heels clicking on floor from walking, etc.) is much harder to control. Impact sound travels through building materials (floor joists, wallboard, etc.) much faster and much more efficiently.
In order to control impact sound, you need to isolate the surrounding material. Some of these problems are “built in” and cannot be resolved easily (or cheaply).
We try to 1) stop floor joists and underlayment from extending under a party wall, 2) provide separate party walls between rooms, and 3) stop roof joists from crossing from room to room.
Obviously it’s too late for those techniques, so now you need to consider techniques for each individual problem.
For doors, I’d try: 1) provide rubber bumpers on jambs, 2) provide weatherstripping to cushion the door when closing, and 3) add closer to control speed of door closing.