Barking The K9 Verbal Language

 Here in Illinois and in Puerto Rico I have spent a lot of time trying to understand the dog's verbal language. Until I listened to the Satos, free ranging Puerto Rican island dogs, I thought dog barking was more limited in scope to intruder alerts or bored and lonely. Scared dog barking was in there too, but I saw it as a mindless pursuit.  The dog was just letting off steam.
Every two - three weeks the Satos do what I thought of as chatter. How long it took me to realize that it was an actual conversation just saddens me. 
That enlightenment came when I recognized that the dog always took off after giving a three woo bark. The third woo is different. I wish I could describe it better. I need to shop recording equipment so I can catch this bark. 
The PBS shows about animals having sounds to say the danger is above or snake documents the specific nature of their vocalizations. I praise the Jane Goodalls of the planet; it is so cool to know this stuff. 
The eureka moment I knew definitively what this bark meant came in the middle of the night when I lay in bed listening to the dogs bark, trying to figure out which voice went with what dog. Stormy, the Sato whose voice I know best did the bark that signals he is going some where. I hopped out of bed in time to watch him trot down my driveway.
My husband, Kirt and I have seen him get up and leave like he has an appointment. When he does this, no coaxing or calling will change his mind. He even ignores my secret weapon, which is the squeak I use when I feed them. That squeak worked to train him away from chasing cars, but not this.
If what I called chatter really are dog conversations, what are they saying?