Oh, I feel for you. Although, it's actually only 1 of mine who is a barking noisemaker...then the other 2 start.....last night, we had a bad rain storm with high winds knocking over trash cans, etc. outside...so of course Foxxy started...then Diva...then the puppy...I was so frustrated I yelled BE QUIET!!! and they did....they scared me(it was 2AM & I was sleep), and I guess I scared them too out of reflex...lol. But I know what you mean about 1 starting something and the others follow...
they do it when they hear the doorbell too..it's like once they start, it goes on and on for awhile...even after the person has come thru the door!