Not trying to get picky here, but Blackhawk, your response makes even less sense than your original statement.
How, exactly, does one scream non-aggressively?
Maybe it doesn't make sense to you, but screaming is pretty much a natural universal language all unto itself.
It's most UNnatural for an attacking human or animal to NOT scream during battle if the outcome is in doubt. Not surprisingly, military organizations have fostered and taught effective battle screaming for millenia.
I remember bayonet drills in Basic Training in 1967 when the DIs practically forced us to scream at the dummy as we ran it through. Guess what? We were MUCH more aggressive and effective when giving a loud scream than when not. They weren't girly "eek" type screams -- they would curdle your blood.
Almost any animal will turn tail if you charge and unleash one on him -- it's than universal language thing saying "you are going to die, violently!"
Learn the vocabulary of the language, but since hand-to-hand combat veterans are becoming scarcer every day, you may have to settle for library research.
"Yes, your honor, I didnt actually identify the man I shot, but I could tell from his aggressive scream that he was a bad guy who meant to do me harm."
It would be a statement to the jury, not a judge, and I would be very happy to demonstrate, just as I'm happy to demonstrate for training purposes, and they're something I'll definitely use should I again get into a serious tussle with man or animal.
In any event, not even the Army holds you responsible for what you do for the first minute or so after you're suddenly awakened from a deep sleep. I'll take my chances with a jury, thank you very much.