I am privileged to be a student at the New York Aikikai, which is the foremost aikido dojo in the United States and among the most important aikido dojo in the world. Seriously.
One of the more senior students there--and there are some who have been studying there since it opened in 1964--is a wiry man who has been called, in a pun on his name, "All Night." Because he can whip my ass without effort, I will use the pun, rather than his real name, to refer to him.
All Night has a method in the dojo: he makes noises like he's in a martial arts movie. Seriously. Upon attacking with, say, yokomenuchi, he will rasp out something that sounds like "hoowah soh!"
I got to work with him for a good chunk of a class yesterday, and I responded in kind, though my own grunting was more Germanic--something entirely reasonable, given who I am and what I do. Evidently, not many of my fellow students indulge All Night in this way; he seemed quite pleased, if the raucous laughter that pealed from him between waza is any indication.
It was a good class.