I can think of at least three kinds of ki-ahps. 1) protect the internal organs during a fall; 2) bring power to a kick or strike; 3) inform a partner of an impending move. I think there is greatest variety in sound in this last one. With partners who work a lot together, different ki-ahps mean different things. Some people's ki-ahps sound like a bark, some people's sound like "huh," some sound JUST like "Ki." Most are short, some are long, it all depends on who and why, and maybe what day it is and what time it is.