Why do MPs shout their heads off?

One question that is never addressed by any parliamentary Question Hour is: why do parliamentarians shout their heads off, especially when one of them is speaking? The mystery is not so much why MPs shout - family traditions may, indeed, be reflected in their public lives - but why they shout incoherently with no one able to understand what they're screaming. Is the whole purpose to merely interrupt coherent speech?

India is a society where volume equals validity. Our TV studio expert panels have merely amplified this parliamentary-cum-bazaar sales pitch trait into our living rooms. Another theory has it that vocal 'MPerialism' is a primal ritual, a kind of parliamentary mating call. The louder you bellow, the more assured you're likely to feel that you've made your point. No one ever deciphers what's being shouted. Only that a whole lotta shouting's going on. It creates the illusion of passion, urgency, democracy in full-throated bloom. Polite, coherent exchange of words, after all, could seem suspicious - too contemplative, reasonable, 'baat mein kuchh kala hai'. Let the records show not what was said, but that there was screaming involved. In any case, parliament is less about persuasion than performance. And volume is the only way of showcasing how much one can truly represent one's people, who can be suitably impressed only by noise.