When we had a flock composed of Barred Rocks and Black Stars they learned to get us out to them muy pronto by making the distress calls of the sort one expects when a predator is right outside the run - or possibly in it.
Is it complaining, or is it conversation? Our flock tends to gather around if I sit for a while and then proceeds to all talk at once. I think the general gist of it is that they're fine, they hope I'm fine, and they wonder when snacks will be served.