We praise ours when she barks at someone at the door. We put her into a sit-stay, which is also praised, if it’s someone ok. Ours is much more visual than sound triggered. She may bark at the doorbell or a knock, but she’s much much more likely to bark and howl if she sees someone. We rarely use our front door, so she’s more inclined to guard the back door…which may be a good thing because it’s not as obvious as the front door. She is pretty good at picking up moving figures in the dark (if they don’t trigger the floodlights) and she’s also set off by our neighbors when they’re in their yard or 2nd floor deck. She’s a lab shepherd mix and weighs around 70 lbs. Not massive, but she’s got a serious sounding bark and her size spooks friends who are small dog people.