I don't know if your yard is fenced in or not. For some reason, guineas just LOVE to be out on the road. I free range my chickens and they never go on the road. My neighbor has guineas. He lives across the road from us with about a quarter mile drive and his guineas will occasionally come down and visit. They wonder up and down the road for awhile and then decide to go back home. I would like guineas but will not get any for this reason. When I was a youngster, our neighbor had guineas and it seemed at least a weekly occurance to find a dead one on the road.
They do chatter alot. Even when they are up at the farm, I can hear them through-out the day.