barking

my model dog noah as suddenley started to bark at anything and everything, from pigeons to cars ........
any ideas , he is driving the neighbours mad

Have you taught the quiet command? Teach him to bark on command and than tell him to stop. Reward and praise when he does so and practice practice practice.

Unfortunately (or perhaps fortunately as it may be!) I haven't any experience with this so I can't add to the training advice above ... have you tried toys to keep him entertained though, and is he getting plenty of exercise? Just wondering if it might be a little boredom perhaps ....??