Why do we tend to shout or scream when applying a large force, like when pushing or lifting heavy objects?

Question

Why do we tend to shout or scream when applying a large force, like when pushing or lifting heavy objects?

Answer 1

Shouting helps to put out more, believe me. That's why we do it all the time in Ti Kwan Do class. I don't know why it helps but it DOES work.

Answer 2

When a great effort is done by the body, you use pretty all of your muscles.  The sound comes from your lungs and vocal chords as a result of muscle contracture from muscles  near the lungs pushing air out of the lungs and through your vocal chords..