That's what I'm sayin'

and besides, the 400-500 people who are actually hearing the noises have a choice to pack their shit and go, or ride it out.

There are little to no accounts of "artillery like noises" for any of the mega quakes that have happened in recent history. I would imagine it is because the sound of artillery in 1811 was a muffled noise compared to todays. Unless you're accustomed to hearing 18th century weapons, a warning like this is pretty useless. Much less, none of the accounts I've found have said anything about it happening days or weeks before the quake. It likely happened during the quake as rubble began to fall in the distance, before shaking began under their feet.

This phenomena is happening in a lot of places, but this is the first that nobody can blame on something else. Bringing up totally irrelevant topics doesn't help solve the mystery or warn anybody.