Nick

“LET ME OUT! At some point your dog is bound to try barking or whining to get out of the crate. This is natural, it’s his way of trying to let you know that he wants out or desires your company. It is important however that you do not inadvertently reinforce the barking or whining by letting him out (or telling him “it’s okay”) while he’s making a fuss. Instead, ignore him until he quiets down on his own. If they’re not reinforced for making a fuss, most pups will learn to settle down and be quiet when left in their crate or sleeping room. If he starts barking relentlessly, and you’re beginning to pull your hair out by the roots, do whatever you need to do to cope (ear plugs? wine?) but don’t shout at him to “BE QUIET!” If you do, you are basically barking back, and as anyone with multiple dogs knows, barking is contagious! Even if your dog understands that you are irritated, you’ve still given him attention, and that, after all, is what he wanted. If you need to get him out of the kennel when he’s crying or barking, distract him with a noise (click of the tongue, tap on the wall, anything that gets his attention) to get him quiet for a moment. The instant that he is quiet you can let him out of the kennel. The one exception is if your pup is trying to tell you that he has to potty. If you think this might be the case, take him outside quietly, give him his “go potty” cue, treat and praise when he does and then put him right back in the crate.”
― Patricia B. McConnell, The Puppy Primer