What does Tennyson mean by "the rustic cackle ... [is] the murmur of the world"?

Question

I am finding the following lines from Tennyson's Idylls of the King quite perplexing:

A thousand pips eat up your sparrow-hawk!
Tits, wrens, and all wing'd nothings peck him dead!
Ye think the rustic cackle of your bourg
The murmur of the world. What is it to me?

I asked a related question on English Language & Usage, and it helped me grasp the grammar of the last two lines. They read: "ye think [that] the rustic cackle of your bourg [is] the murmur of the world."

But now my question is, what do those two lines mean? What does the "murmur of the world" refer to? And what is the significance of that murmur being equal (or unequal) to the "cackle of your bourg"?

Answer 1

The background to this passage is that Geraint has come to “a little town in a long valley” and, finding the town busy with people and activity, has asked three times for the cause, to be told only that it is due to the “sparrow-hawk”.

What the town knows, and Geraint does not, is that a tournament will be held on the next day, with “a golden sparrow-hawk” as the prize, and that the knight who wins the tournament, and who awards the prize to his lady, thus declaring her the fairest, will have “earned himself the name of sparrow-hawk”.

At the third time of asking, Geraint loses his patience and replies as quoted in the question. You need to know this meaning of “pip”:

pip, n. 1. Any of various respiratory diseases of birds

_{Oxford English Dictionary.}

Tits and wrens are tiny birds, “winged nothings”, that under normal circumstances would be prey for a sparrow-hawk. So what Geraint is saying is that he wishes the sparrow-hawk were so enfeebled with illness that it could be pecked to death by these tiny birds.

Finally, Geraint complains that the inhabitants of the town foolishly imagine that everyone in the world knows their business: that is, they think their “rustic cackle” (cackle = chatter, gossip) about the “sparrow-hawk” does not need explaining since it is the “murmur of the world” (that is, on everyone’s lips).

Answer 2

It means, metaphorically, that you think your extremely limited experience is everything in the world. The person addressed is familiar with the birdsong in his neighborhood ("the rustic cackle of your bourg [or town]") and thinks it extends to the world ("the murmur of the world" -- everything to be heard in the world).