That's prosody. The difference in meaning isn't a consequence of the presence of the question mark, although that's what people think of as "grammatical." The presence of the question mark and the difference in meaning are both consequences of the prosodic differences between the two sentences.
This shows one of many challenges inherent computational linguistics: "the written word" only encapsulates a small part of what it means to "speak English" or "understand English."
As a nice benefit, it makes the sort of grammarian who obsesses over the written word look (rightly) like they're missing the forest for the trees.
While you have a point in there, some things are still missing. In my opinion the buffalo sentence doesn't have enough prosody to ever make the verbal version intelligible without explanation. The sentence in the OP does, but it's also missing mandatory punctuation. Punctuation conveys a solid fraction of the information prosody does, and sometimes even contains information prosody doesn't.
http://en.wikipedia.org/wiki/Prosody_(linguistics)
Consider the difference in how one says
vs That's prosody. The difference in meaning isn't a consequence of the presence of the question mark, although that's what people think of as "grammatical." The presence of the question mark and the difference in meaning are both consequences of the prosodic differences between the two sentences.This shows one of many challenges inherent computational linguistics: "the written word" only encapsulates a small part of what it means to "speak English" or "understand English."
As a nice benefit, it makes the sort of grammarian who obsesses over the written word look (rightly) like they're missing the forest for the trees.