Learning Ninjutsu : Spirit shout

The Ninjals KIAI, or "spirit shout" is a natural release of Breath and noise that accompanies the expending of physical and mental energy. We see a natural KIAI often in daily life - giving a yell at the moment of lifting a heavy object, dogs growling and barking while fighting, the noise of a fire-cracker going off, and players giving a shout upon scoring in a sports event. There are four KIAI types in the Ninja's fighting method. The four KIAI are not specific words, but rather specific situations or motivations prompting the shout.
ATTACKING SHOUT - similar to the "Rebel yell" or Indian war whoop familiar to Americans. Using an "eiyee" or "ahouw" type of sound at the onset of the attack gives the fighter a psychological charge while perhaps startling or momentarily stunning the opponent.
VICTORIOUS SHOUT - similar to a bowler's "awright" as the pins topple, or a mathematician's exclamation upon solving a difficult problem. After a series of blows have been dealt, the fighter lets loose with a "yaaah" or "iyoh" type of sound, close to the opponent's ear if possible, to further convince the opponent that the fight has been lost.
SHOUT OF DISCOVERY OR ENLIGHTENMENT -.similar to a detective's exclamation upon finding the conclusive piece of evidence in a mystery, or the "o-ho" of a card player discovering his opponent"s strategy. The fighter uses a "toh" or "shah" type of sound to accompany the mental charge upon discovering his adversary's movement pattern, or hidden weapons.
INTERNAL SHOUT OR "SILENT KIAI" - a low, rumbling growl made up of vibrations so low in pitch that they are Inaudible. This is the highest form of KIAI, and would sound similar to "ah-unn" if it were audible.