Hi. We live in a 1950s semi, where the noise carries through from next door and back really badly. We can hear a lot and they're not particularly noisy neighbours and vice versa. Has anyone ever had soundproofing done? If so, does it work? Does it involve literally putting another wall in to "trap" the sounds? Also, is it massively expensive? The son next door has just got a girlfriend, and DH and I can't bear to listen to her amorous shrieking any more!!