Dogs neglected by owners tend to bark incessantly, you need to put the neighbour in the garden, give the dog the house and see how it plays out.
Our latest neighbours allow their dogs to bark (we live in a high crime country) none get up to see what is happening. My question if the dog is there for protection, surely you will lift your arse and go see why a dog is barking? They don't!
If the dog is a pet, as my previous dogs have been, they sleep inside for their own safety, as I mentioned South Africa has become a crime riddled country, a dog in the house will alert you when sleeping to any movement outside. Not only are dogs stolen to sell, eat who knows, certain breeds are stolen and primed for dog fighting, so all in all certain owners should never be allowed to own dogs.