It is well known that non-verbal conversation is significant to dogs. Dogs can detect things humans are never even aware of, and react to seemingly innocuous things or “phantom” stimuli, sometimes in extreme manners. They also come to understand us over time to a degree where they seem to know what we are thinking, sometimes before we do.
Perhaps dogs are telepathic. They communicate over far longer distances than we can appreciate, and the sounds they make are solely for our benefit: “to keep us in the loop,” but only when necessary.
After all, humans provide food, clothing and shelter for them, cater to their every need, constantly seek to amuse them, and leave them be when they want to sleep or otherwise be by themselves. I suspect that they are quite happy with this arrangement, aside from that closed door thing, and cultivate our behavior to meet their needs.