I am not a pet owner myself, but I imagine that it is has been difficult for you to train your dog to obey. It appears that you taught him the "speak" command and he took an unusual liking to it, especially during the hours when people are trying to sleep.
I can't imagine that there's any way you are unaware of your dog's unfortunate combination of noise and nocturnal waking hours. If you have ear plugs made out of sound-proof glass, I would love to borrow them. Whether or not you are accustomed to the incessant barking, however, I must insist that you do something to stop it.
I have a job where I have to wake up very early. I have an alarm for this. Therefore I do not feel the need to be awakened every half an hour after 10 o'clock. I am not disputing your right to own the dog, nor his right to loudly voice his canine opinions. However, this city does have a noise ordinance law, so I must ask that after 9 o'clock P.M. you mute him until 6 o'clock A.M. at the least.
I do hope this doesn't cause you any untoward inconvenience. Perhaps you could muzzle your dog at night or train him to stop barking on command. I thought up many solutions to the issue during these last few sleepless nights, but unfortunately they all involved an inappropriate amount of violence. I leave the method to your discretion, but please resolve this matter soon. I really need the sleep.