@ shortgrass: When chickens talk, it is an expression of content, even basic happiness. They also might want to share their thoughts with you, whatever they are. (Such as: "I love it when you come to visit. Why don't you visit more often?" or "You should have seen the big bug I just found, chopped up, and ate with delight.")--When chickens sing, it is an expression of high emotional happiness.
Chickens have a whole variety of vocal expressions. They all have different meanings. They can express excitement. So the typical "guck-a-guck-a-guck-aaaaaaa" (for instance, after the accomplishment of laying an egg). They can express discontent with short, hacking clucking. And they have a variety of other, differentiated noises to express other emotions and purposes, from interacting with other chickens (or other species) to scaring away imagined or real dangers to screaming loud for help. As an ESL-writer, I am not familiar with the English vocabulary for the different sounds that chickens make. So I cannot describe them and their meanings any more detailed.
Yet, growing up with chickens (and later with cats), I speak some chicken (and cat).

So my translations from "Chicken" into English might include some fantasy but are not totally unfounded.