Soundproofing a room

[TomaszIsMineBitch]

Hi all

I have recently got new neighbours who have a small baby. We have only been here a couple months ourselfs. I noticed last night that the dividing wall between my ds's (aged 11 and 9) wall and their babys is very thin and we can hear the baby cry as if the baby was in the room with us.
This is fine and doesnt bother us as babys will cry but im worried that my boys may wake the baby as they can be quite loud at times.
They are not bashing about and making a nuisance but just general kids playing sort of noises and sometimes brotherly arguments.
How can i soundproof the wall so that my dc dont wake the baby? It is a small room oddly shaped so that their bed is up against the dividing wall.

Bookcases (with books in) are great soundproofers. You could have a bed pushed up against one or two as long as they’re secured and you can trust your dc not to mess about (I’m still in toddler years so may be too risk averse there).

Books can be picked up for pennies from charity shops/car boots for the bottom shelves. Plus it’s educational!

There is special soundproofing boards similar to plasterboards, but it would mean stripping the wall surface adding the boards then replaster and decorating.

Cornettoninja thats a good idea and wouldnt be too difficult as my dc love reading. I often find books on there beds.

justchangingagain our home is rented so i dont think i would be allowed to do that.

Thanxs for the suggestions