We had a beagle who was pretty badly behaved. Barked all the time, and in general just wouldn’t calm down. Had her for two years. My parents solution to the problem - send her back 
I had a beagle growing up and I bought one about a year and ahalf ago. She never barks inside, but once she gets out, the baying begins. My neighbors don’t seem to mind so I guess I have it pretty good.
I also trained her to ring a string of bells when she wants out. Pretty easily too. House training was a chore, but when isn’t it?
In general, if bred well, repeat BRED WELL, beagles are great dogs. The problem is that too many people buy them from puppy mills, friends or other dubious sources. They then blame the dog for its genetics.
Not fair if you ask me…
I grew up with a beagle-terrier mix name Bristleface. Talk about a spaz. I loved her so. I was pretty much impossible to get out of bed in the morning. My mother found the answer: Bristleface. Bristle loved to greet me in the morning. Oh yes! Her joy could not be contained. It required expression, which invariably involved doing the jitterbug on my head. Bristle could leap approx. 20x her own hight. Often she would bounce straight up and down for no discernable reason, and go from where she was at about my knee level to eye-to-eye.
So, morning has broken. Like every other morning. In my half-wakened stupor I hear it: the creak of my bedroom door. There is a momentary pause. Then my mothers says, very quietly, “Get him.”
Bristle is airborne. I open my eyes to see her in the midst of a parabolic arc, heading straight for my face. Her front paws land somewhere on my neck and chin, her rear paws on my diaphragm. Hence, I am simultaneously given a blow to the larynx and getting the wind knocked out of me. Bristle bounces. She quivers and shakes. She is SO EXCITED. She is SO HAPPY TO SEE ME AWAKE. She licks my face while stepping on it, twirling about in place when she can’t sit still long enough to stick her tongue up my nose or in my mouth. I’m literally screaming “aaaahhhh! aaaaaaahhhhh!” and this just seems to tickle her fancy more. I must crawl out of my bed on my hands and knees to get away. Satisfied, Bristle trots, nay, bounds out of the room to rejoin my mother and father downstairs, who will congratulate her on a job well done.
This happened every school moring for five years. I am not lying.
Needless to say, I developed a really ambivalent set of feelings about all small, spastic breeds of dog that I haven’t fully resolved. I think the bay is what gets to me the most. Bristleface, despite her terrieresque mug, had beagle coloring, and the beagle bay, of astonishing volume given the size of its source. She would bay at anything. In all seriouness, she bayed at the full moon. I thought that was a load of baloney until she started doing it. I’d go outside and say “It’s the frigging MOON you stupid, stupid dog, now SHUT UP!” but it didn’t matter.
I dunno, my friend. You’re dealing with forces perhaps beyond human control. I don’t know what perverse mind came up with these creatures in the first place. Maybe they have a secret antidote stashed under a mountain somewhere in a deep, nuclear-bomb-proof bunker. Until we find it, my only rememdy is to develop a kind of sadomasochistic and uncoditional love for the wretched creature like I did for my dear, departed Bristleface. May she rest in peace.
Wait, peace? What am I saying?
Well, I’m a little unsure that a “time-out” would be very effective, since dogs have extremely poor short-term memory and very bad at grasping the concept of cause-and-effect. By the time you close the door and walk away, the dog has probably completely forgotten what he did that made you so mad. Then, he finds himself isolated from his “pack” but can’t remember why. All he knows is that he’s all alone. Time has no meaning to a dog, so putting him in the room for a couple of minutes would be just as “effective” as fifteen.
Any punishment a dog recieves must be IMMEDIATE-- even a delay of a few seconds can cause the dog to disassociate his actions with the consequences.
My suggestion to the OP is dog biscuits and peanut butter. When my mother’s dog was a puppy, it enjoyed barking constantly. My mother didn’t enjoy it as much.
She broke the bad habit by distracting the dog with peanut butter on a dog bisquit whenever it started woofing. The peanut butter made the dog’s mouth sticky, so it was five or ten seconds before she finished eating the treat. By then, she’d forgotten that she was barking in the first place. Mom would then give the dog a command that she knew, such as “sit” and then praise lavishly when the dog obeyed. Later on, all she had to do was command the dog to sit, and then praise her to stop the barking.
The point is to distract the dog from what it is doing. You’re never going to completely eliminate the habit, but you might be able to control it.