Danny, you got everyone on here whooped, on callin' days I beleive. I've only been doing it for 23 years. I was around chasing with grey hounds in my early years, so I got a late start in the callin' game.
BUT thing is, I call wide open country, and I've seen multiple times a coyote not respond to more than one sound, only to respond to a different sound. That's the beauty of callin' open spaces, you get to see how they react, often from the very first note on a stand, and ya learn alot by observing those reactions. I can't say that I've ever seen a coyote that was responding, maybe very slowly or even sitting and listening, only to change sounds and watch the coyote run off because I "confused" it with another different sound, it ain't happened! I have witnessed times where a coyote will sit way out there, not respond to any sound, so maybe a guy should just stick with the same sound until the coyote finally looses interest and walks off? I don't think so. I've seen too many of them respond to a changed sound to put all my money on one sound.