Dog story about Finlay

My dog is Finlay and he is a red american cocker. I have a daycare in my home and he loves, loves, loves the children. He actually howls and cry’s when they cry. Im not sure how to deal with this problem as he gets louder than they do. When a child crys on tv he does the same thing and we have to lower the volumn until he stops. He will even do it in his sleep if he is sleeping on the floor and a child crys on tv, he starts wimpering. Anyway, Finlay is a very good dog and we love and appreciate him very much. But, I haven’t been able to become the master here and I’m sure it comes from lack of knowledge. When the door bell rings or someone knocks on the door, Finlay barks. This is a problem and having a business in my home, my door is busy alot of the time. Can you suggest how I can handle this situation. Thanks for your imput Shirley C