Sounds like he's wanting your attention.
Try putting pennies in a soda can/beer can. Shake it in front of him
when he barks unnessarily. It might frighten him but that's what you
want. Leverge!
It's the only thing that has helped me when Buddy
went through that period. I still use it when I leave in the am.
I show him the can and threaten to shake it before I leave. Because
he wines and howls when I do. It works everytime, for us.