Different Pronunciations of "OR" in "FORK" & "PORK"?

Justin   Thursday, August 26, 2004, 13:30 GMT
Some Americans dictionaries, such as the American Heritage Dictionary and the Merriam Webster Dictionary, divide the pronunciation of "OR" into two kinds.

fork [fo:rk] ("faw + rk")
pork [pOurk] ("poa + rk")

short [sho:rt] ("shaw + rt")
sport [spOurt] ("spoa + rt")

But I don't realize the difference when I listen to Americans speak. And I can't find the regular pattern. So, why do American dictionaries of English make this rather "strange" distinction?
Mxsmanic   Thursday, August 26, 2004, 14:28 GMT
I don't hear any difference, either, and American is my native language. Most Americans don't make a distinction between these words.

In any case, the differences are not phonemic, so you can pronounce them in whichever way you choose. I usually pronounce the vowel as [o] for all of the words you list.
Ben   Thursday, August 26, 2004, 18:06 GMT
"SpOurt" would be something of a Southern pronunciation, since all "o" words like "bought," "caught," etc. are often dipthongized into "Ou." I certainly have never found any distinction between "fork" and "pork" in American speech.
mjd   Thursday, August 26, 2004, 19:52 GMT
Definitely no distinction in my pronunciation.
Juan   Thursday, August 26, 2004, 23:52 GMT
It's the same drawn out O isn't it?