I think it depends what type/species of dragon you're referring to
I'm not sure what noises Ventus would make, but considering her redesign, probably more birdlike, or chirpy(?) Though mostly silent.
Whereas if you are referring to a feline-based dragon, then that would totally make sense that it would make purring noises.
And a canine-based dragon would probably make barking noises.
Or whatever you want, really. Dragons are fantasy/mythological creatures. You can make them make any noise you want them to have