When we first got our pup he was always excited when the doorbell went or he heard people outside, now he is 11 months he has decided that if there is a noise or doorbell he goes crazy barking like mad charging up and down.  If someone comes in we have to let him get the attention first to check them out then he lies down but if its a stranger he won't leave us until he feels evrything is ok.  Its quite funny but the blinds get ripped down if we don't get to the door first should I leave him to protect us or tell him its wrong.  Its funny though if its my husband coming home any time day or night he knows its him before he comes through the door and never makes a sound.

I feel you've got to make a decision now which you should perhaps have made when he was a little pup - is it acceptable to YOU to have the dog answering the door.  If not then you should start to train him to carry out the behaviour you do want when the door bell rings.
He can probably tell it's your husband by his footsteps BTW

Probably recognises the sound of the car first if he drives one.