Wife and I have bought a home and income property as our first house, having rented one in the past we thought sound travelling wouldn't really be too much of an issue. However the house we rented and the house we've bought must be made of quite different materials we are hearing much more than we did in the past. 

Some googling around suggests this is a fairly common problem with many US based companies that specialise in helping to fix this. Problem is I'm not finding any NZ (Auckland) based ones. We do realise that nothing will fix the problem 100% and that it won't be very cheap, but keen to get a few quotes and assess our options.