When we shout or scream, the voice is behaving like a badly designed violin or organ pipe. Extreme pressure from the lungs compels the vocal folds to vibrate violently. This sets up forced resonances in the air cavities. But far too much of the sound for comfort comes directly from the vibrating muscle of the folds themselves. The folds soon become tired, and (surprisingly rapidly) inflamed. Eventually they give up completely, like any other overstrained muscle, and the voice disappears.
To be heard at a distance it is much more effective to sing, providing you have a good technique. Classical singing technique uses the resonating chambers of the human body enabling it to behave like a malleable organ pipe.
The vocal folds (also known as vocal cords) in the human larynx work in the same way as the reed in an organ pipe. Air passing out of the lungs causes the tensed muscle of the vocal folds to vibrate. The human being has an advantage over the organ pipe. Unlike a fixed reed, the vocal folds can stretch or contract according to the pressure of the passing air.
We also have another vital variable; the ability to change the shape of the resonating air chambers in the upper torso and, more importantly, in the head and neck. The balance of pressure between the upper and lower cavities dictates the frequency and quality of vibration of the vocal folds. The infinitely variable shapes of the cavities add their own qualities to the sound.
