It is valid to compare vocalisation between species. Humans have it mostly under voluntary, conscious control. We do sometimes make sounds unconsciously or involuntarily, but it's not often. It's very likely the same considerations are at play for most vertebrates as well. Dogs clearly bark, growl, whine in response to what's going on around them. As well as screaming in pain if you e.g. accidentally stand on their paws while wearing heavy boots. It's almost certainly consciously controlled, because you can tell them to be quiet! I found it quite funny when I told mine to shut up after growling and barking for a while at stuff going on outside; the odd mini-growl showed they were trying to keep a lid on it not entirely successfully!
Neurologically, the essentials of the nervous system are almost entirely the same in higher vertebrates. Some things are more elaborated in some species, but the fundamentals are pretty much identical. There's even a large amount of similarity with invertebrates like insects. Which makes sense when you consider that all animal life has a common ancestor. I would be extremely surprised if vocalisation wasn't entirely voluntary in every single vertebrate species. I'm sure there's some behavioural and learned component to it, of course, but that's rather different than whether it's voluntary or not.