Some dogs are just simply more vocal than others.
Don't underestimate your dog's size and the size of its bark. A barking dog, even a small one with a shrill bark, can upset neighbors, and you. The constantly barking dog has already reached a saturation point, and tells us nothing, other than that it needed help a long time ago. Crate training does help barking training too. Stop the dog before it escalates and is so excited it cannot hear anything.