Yeah, using a layer of insulated acoustic plasterboard is a good idea.

Hi there,

You can install a layer of insulated acoustic plasterboard and or acoustic matt to reduce the reverberation of sound. 

Hope this helps
Michael 
MLA Architecture Ltd

agree that it's unlikely you have a cavity to fill.

as already said you can put up boards/foam but it's much less effective...

If it’s a terraced period house it’s unlikely there is a cavity in the wall that you could fill. (Not sure about more modern terraces but suspect also unlikely). You’d need to apply some soundproofing material to your own wall. There’s lots of options, they vary in cost, effectiveness and ugliness!

You can get pre made foam or cork panels you just apply to the wall, or for a better look fit two layers of soundbloc plasterboard to the entire wall and then paint to match (but you’d also need to refit any cornice, skirting, carpet). Or would a built in wardrobe or bookcase be an option? If so that would help a lot, especially if you put soundbloc at the back of it.

Has anyone had experience of filling an existing wall with insulation? I’m not sure what the options are - foam?
Our bedroom wall is next to the lounge of the flat next door and sadly some fairly inconsiderate people live there.
Any company recommendations, suggestions or experiences greatly appreciated.