This definitely happened with a foster pup I was watching. She use to growl and bark at my roomies, and it became less and less. I only had her 10 days, so I didn't break her from the habit 100%. I did say "quiet" and immediately offered her praise and cuddles, or a treat for being quiet for half a second. I didn't give her much time to keep barking as I was already rubbing her head.
__________________ Littlest JakJak 
We miss you Kaji  |