You may want to use the sound that is most the prevelent prey species in your area. However i don't think it really matters to much what sound you use. Coyotes are by nature curious animals and will respond to most sounds. I have used elk bugles and cow elk yelps out here in the middle of the desert and have had them respond to them. Think you main concern should be cover and scent. I also have a Foxpro and during the course of one week killed 15 coyotes, 1 fox and 1 bobcat, also called in 7 javelina. Good luck to ya.