in the 4 MA schools i have been to, they all had different opionions on when to kiai (while doing basics not in kata) 1 WTF tkd school was the first of the technique. so say you are doing low block, and change to high block, there is a kiai. 2. ITF tkd school, kiai on all attacking moves, not blocks 3. shotokan karate, generally we kiai on the last technique in a set, usually the fifth. ie, moving forwards, 5 times kiai, then move back 5 times and kiai. 4. WTF school. kiai on everything. even swapping stance. CRAZYNESS.