GSD puppy is becoming so protective that he now barks when I make a phone call/Skype etc. Help!?

I have a 10 month old dog who has become increasingly protective of me and the house/property. When he hears someone out front he goes nuts, even more so for the doorbell. Now when I make a phone call and he hears me go "Hi How are you!?" he thinks someone has entered the house & goes nuts, and we sometimes have trouble calming him down or helping him realize there is no one there. Anyone have any recommendations for this nutball?