Martin are you asking about the actual sounds that a hen will make? If so the yelp is the most common. But all the sounds she will make are all effective in the right situation.There are different types of yelping plain yelping, soft tree yelping,lost hen yelping,also gobbler yelping can be effective.Then there is clucking and cutting and purring. And the kee kee all these sounds have there place. confused yet?