I always hear a distinct man scream and woman scream in tons of movies. It usually when the person is killed, murdered, or being mauled by zombies. Why the hell is this? I know I'm not the only that has noticed this.

Yep. It is in Star Wars and Indiana Jones. I know I've heard it in Dante's Peak. I'm watching 30 day of night and heard it again. Thats why I asked. Still it in a ton of others.