I can do without.

That's actually from a Tears for Fears song. They were doing shouting therapy or something when they wrote it.

Anyway...

Most people forget that a shout is a big gust of air passing over your vocal chords. A shout can hurt you no more then...for example..."A big gust of air passing over your vocal chords."

Really most of the time there's no real need to shout. Waste of energy if you ask me. Perhaps, if there's someone trapped in a building, or if your working on a construction site with loud machinery, might be handy.

Gassho