I'm at a loss of what to do, what I've started to do is just go to him and say quiet. I know this is giving him attention but if I ignore it he carries on.
Does your dog know what quiet means?
Have you taught it?
If not then you might as well say supercalofradgalisticxpealidocious to him because it will have as much meaning
I taught quiet with the clicker by first teaching my dog to bark on cue by revving him up and getting him going and then stopping the game and when he stopped barking click & treat repeated this on numerous occasions and then started to add the cue when the barking stopped.
Once he associated the cue with the action he would quiet on cue.
Have you ever tried clicker training?
It works Big time.
I took Bayley on last February, scared agressive to people and dogs and very gobby, he liked the sound of his own voice.
What did I do clicked for quiet and added the cue.
He now quiets on cue but also I must have clicked for qiet in a sit as he always now sits on the same cue as well
Give it a try or get a trainer to help you.
Mark