Originally posted by Nick
"O-sensei's kiai was a high, ear-piercing shout that you could hear almost half a mile away, and it would just stop you ded in your tracks. It was deafening, it hurt your eardrums. It permeated your whole body, your entire being, you could feel it spiritually, mentally, and physically. It made you weak, made you sometimes want to just collapse... With O-sensei, you didn't jump, you just collapsed, you felt instantly sapped."
From Aikido Kyohan: Complete Aikido, pg. 73.
Hope it helps,
There is a live recording of O Sensei's kiai on an early 1930's film made for pre-WWII Japanese propaganda. I've been told by others that O Sensei had a high, reedy voice. This sounds true, since his kiai in the film, was more like someone stepping on a cat's tail than some god-like thunder.
Of course you can say that primitive sound equiptment didn't do O Sensei's voice any justice. You can judge for yourself. The video tape is carried by AikiNews.