I don’t think should is appropriate when talking about differences in accents. Accents change over time and distance. Differences are differences, period. There’s no should about it.
Several sound samples of speakers with different accents are available in an audio archive at the home page of the alt.usage.english Usenet group. You can take a listen to some midwestern accents to check out how the vowel mergers work. There are several such sets of vowel mergers in the Midwestern accent. I’ve posted this list before, but here it is again for the sake of convenience –
And Americans for the most part are rhotic, which means an “R” following a vowel is pronounced as an [r] and doesn’t merely affect a change in the preceding vowel. For the sake of courtesy, I would entreat non-rhotics, when spelling things phonetically, to avoid using an “R” to show a change in a vowel.
I was badly misled by this when I first visited Italy at the age of 12. My Italian phrase-book’s pronunciation guide represented the Italian long [a] sound as “ar”. This is because it was written by and for non-rhotic speakers of British English, and not for rhotic Hiberno-English speakers who would dutifully reproduce the “r” sound.
My favourite example is two girls I heard arguing over the correct pronunciation of the word “bath”. The girl from Kent said it should be “bahth” (long “a”). The girl from Liverpool disputed this, saying “there’s no ‘r’ in ‘bath’”.
Moriah wrote: “Well, there’s the short ‘o’ sound represented in lot, cot, pot, hot, frog, hog, dog.”
But no one I’ve ever heard uses the same short O (ah) sound as in lot and pot, in the word dog. They usually use the ‘aw’ sound instead for dog. Also for frog and hog, except for my wife as noted above.
I expained the difference to her last night as follows: When you see a picture of a cute puppy, you say, “Awwww…” and when you have a moment of pleasure or insight, you say, “Ahhhh…” So in effect, there are no rhymes in the sentences, “The teacher taught the tot” or “The puppy pawed the pod.” The first sound is aww, the second ahh.
Also, we learned the long O sound as the one in cone, toe, blow, etc.
By the way, hyjyljyj in your examples, In my Ohio accent, I’d parse the AH words and the AW words differently than you do. It seem to me that your categories are:
(1) AW, and
(2) AH/Short O.
In my accent, I group them differently. The two categories are:
(1) AW/Short O, and
(2) AH.
To me, “short O” is the same as AW. AH to me is an “A” sound, not an “O” sound.
So under AW, I’d have – con, cocky, raw, cot/caught, pod/pawed, bother, sod/sawed, walk/wok, etc.
Under AH, I’d have – Kahn/Khan, khaki, rah, father, etc.
