
I've also had problems with neighbours, not through noise, but smell (although I do think this particular neighbour is particularly sensitive and I have an ongoing dispute with him and hedges - another story!). My 2 are 12 years old now and as much as I love them, I won't be having any more unless I move to the back of beyond with no neighbours. And the whole defra thing is such a palaver.
Mine are contained in a small fenced-off area in my back garden, which is fenced with a 4ft fence, they've never got over that, although they have managed to butt the panels off a gate and got through that - it's now suitably reinforced.
ETA: Another point is that the girls tend to be noisier than wethers (castrated boys), especially when coming into season as they call for mates!