Kiai

Combat Kiai

In Taekwondo class or in no-contact or semi-contact free-sparring, we kiai with the mouth open. However, in full-contact free-sparring or an actual fight, opening the mouth makes you vulnerable to losing teeth or a broken jaw. Therefore, in a combat situation, it is best to use a semi-silent version of the kiai and keep the mouth tightly shut—make a sound similar to the puff sound boxers use.

Kiai Distracts Opponents

In March 2008, Neuroscientist Marcel Just, director of the Center for Cognitive Brain Imaging at Carnegie Mellon University in Pittsburg, PA, reported the results of a study of 29 volunteers who used a driving simulator while inside a MRI brain scanner. The subjects had to steer along a virtual highway, both undisturbed and while hearing a true or false question. While in the listening situation, MRI brain scans found a 37% decrease in activity in the parietal lobe, which processes spatial information, knowing where you are in space. There was also a decrease in activity in the occipital lobe, which processes visual information.

These data show that listening to and processing puzzling information disturbs a person's ability to react to a situation and make the proper response to the situation. When facing an attacker unused to hearing a kiai, a kiai may give you that split second edge you need when responding to the attack.

A 2011 University of British Columbia study found that people watching video clips of tennis matches reacted more slowly and predicted the balls diirection less accurately when players grunted while returning a ball. The grunt was distracting and blocked sound cues, such as the sound of the ball hitting the racket, which made it more difficult to judge the speed and spin of the returned ball. Using a kiai when attacking may have the same effect on an opponent.