There is some silliness in martial arts about the 'ki-yi' sound.
Well, it is not all that silly, but it is difficult to teach, yet essential, especially for a woman. 'To' a woman? Whatevah...
Singers have the ability, naturally. To call up the power from their center and project it. Forcefully.
Imagine your kid is in the parking lot, and about to dart out in front of a car, and you expel the words that stops them dead in their tracks, and everybody in the parking lot turns and looks at you in surprise.
Yeah, that's it. I took plenty of martial arts before I entered the military, but I never knew how to yell until I had to yell at a group of men. Make them move, or stop, or turn, or just cut their shit out.
I have been accused of sounding like a Drill Instructor. Guilty as charged.
And that ability to burst forth with a blast of sound will freeze an opponent, center your 'chi', and give you the edge. Ladies? Your voices are in a higher range. Cough out the sound from your abdomen...roar. It will startle the crap out of a man.
A timely shout can mean the difference between life and death, or ass-rape.
Learn it, love it...live it.