I talk to my horses, especially at shows. I think they find the voice soothing and it kinda calms me down as well. Yerr, people might think I'm crazy but if it helps my horse and I do our very best, then I couldn't care!
However, I don't blurt out "C'mon RickStar, we gotta beat number 56" because that's just rude and would make me look a bit arrogant.
No, I just say words of encouragment. I guess its sort of a pep talk for me and the horse.