I am a parent, so I can answer your question with respect to children: raising your voice does not do anything except escalate the discussion into an emotional melt-down.
With respect to people you deem to be idiots and trolls, we have known the answer for a very long time. One of the more amusing bits of advice about the matter came from Mark twain:
"Never argue with a fool, onlookers may not be able to tell the difference."
I agree that yelling at children doesn't help. But I'm wondering if you would debate with a child, or try to persuade him with good ideas, or would use some other sort of approach that isn't yelling or persuading?
With respect to people you deem to be idiots and trolls, we have known the answer for a very long time. One of the more amusing bits of advice about the matter came from Mark twain:
"Never argue with a fool, onlookers may not be able to tell the difference."