Mine definitely calmed down. It was headache inducing before and actually hurt my ears. Are you trying to say I've deafened myself?
Think about it, there will be some difference in exhaust not will all of the following happening
1) ECU adapts to exhaust probably changing fueling etc
2) Carbon builds up inside exhaust after a few hundred miles.
3) The packing in the silencers will also break down a little
I think if you found the wrong copper in a bad mood you'd get a slap on the wrist at least. I think Lexx or lilsheepshagger got pulled over before. I just tend to not accelerate when passing police whether it be holding the clutch in and coasting past them or just holding the revs (depending on which gear) just incase