We bought our house just under a year ago. When we bought it, they ticked the box on the form that says we have never had any disputes with our neighbours. It turns out that this was cobblers of the first order. They had regular arguments about the noise our now next door neighbours made, complained about them, and even went round and asked them to shut up during viewings.
Now next door are noisy, irritatingly so. They have a barking dog which goes off in the night (and they sleep at the front so don't hear it), and a teenage son who plays music so loud that I can hear it in every room in the house (oh how I am looking forward to the summer holidays...) and you can hear them in the garden all the sodding time. But having said that, they are generally reasonable (and we might shell out and get some headphones for mr teenager).
But is there anything we can do now? I don't know if we would have bought the house had we known - perhaps not, as I went through a really bad noise nuisance case when I lived in London. But we might have done.