Hi, I recently bought a house, all of the downstairs walls are brick and have pretty good sound properties. However, most of the bedroom walls are plasterboard/stud and you can clearly hear even normal speech through the walls.
As I understand it, even 2 sheets of thin plasterboard with a ~5cm empty cavity on wooden stud work should provide much better sound resistance than this. Are there any particular wall construction issues that could cause this high level of sound transmission? Is there anything I could try before taking the wall down and sticking up some resilient bars/sound resistant plasterboard?