It seems like smaller dogs like to bark a whole lot more than larger dogs. As you go for a job down your street, you might hear many smaller dogs yelping at you through the owners' front windows, but it seems like all the larger dogs are nonchalant about your presence.
There's little scientific evidence to suggest that smaller dogs bark more than larger dogs, but it certainly seems that way from experience. Alexandra Horowitz, the author of the book "Being a Dog," explains why that's the case in this video.
According to Horowitz, it might just be a small dog's way of compensating for their smaller size. By making a bunch of noise, they assert their dominance over their territory in a way.
Larger dogs are typically mellower than smaller dogs, barking less and lacking all the spontaneous energy that smaller dogs seem to have day-to-day in comparison.
While it could be over-compensation on a little dog's part, more research is needed to learn whether they bark more, and more importantly, why.