At the end of my tether.
Have a 2ye old dog and a new pup of 14 weeks.
Older dog has always been grumbly. If he hears a noise he will sort of buff under his breath, unless it's the postman then he barks. No big deal.
But since new pup arrived its like they egg each other on.
The older dogs quiet buffing kicks off the little dog barking, which then makes the big dog bark fully.
For instance this morning, around 5am one of the kids gets up for a wee. Older dog does an inquisitive buff and shifts in the bed, little dog goes mental barking at him, then the kids, big dog joins in.
Happens again when kids get up for school.
I don't know what to do or how to stop it kicking off 
I have grumpy neighbours and I'm scared they'll report us to the council or something.