Neighbour complaining about dog barking?

I have 2 GSD dogs, my youngest 20 months sometimes barks at night and it annoys me too, not that it is continuous - she may bark for 2 - 3 mins but at night it feels like forever- but what she is barking at is the sound of other dogs barking in the distance - I have heard them - obviously my neighbour hasnt as they are that faint. She also barks if she hears strange noises - to which my neighbour never complained about when they looked out their window and realised it was an intruder in their garden at one time. So what would you do. Dogs bark - full stop, dont particularily want get her a collar, like I said the barking is NOT continuous.