When I began my practice in 1966, kiai's were generally thrown in on the last rep of each drill. They were also firmly entrenched in kata, usually two in each, at specific places within the routine. These places seem to be accepted as part of the style's kata, as much as a punch or block, sometimes found across different styles. We all know the purposes of the kiai, but as I delve deeper into kata, questions come to mind. Aside that they generally occur during a strong attack move, why are they in the kata at all? Were they always a part of kata, as taught by Matsumura or Higaonna, or something added in later, perhaps to conform to some notion of ferocity to impress the public? If later on, when? Why do they exist in all the kata I know? Was it found necessary to put them in all? These days when practicing alone, I often omit kiais. If the "ki" in kiai means spirit, is that not an internal and personal thing? If so, why should the time and place of it in kata be determined by some outside authority or convention? Shouldn't I be free to determine my own spirit at the time and place of my choosing as the feeling explodes spontaneously from within me? Reviewing my post, I see there were more questions than I realized. Perhaps too many for something as common and accepted as a simple kiai. But, as I have learned from my long study of karate, there is significance to everything.