Today you said"If it is essential to symbolize the central quality explicitly, then we have diacritics available: [ä] or [ɐ̞] or [ɑ̈]. But it’s better to state such details once and for all in the transcriptional conventions, not repeatedly in a transcribed text."
My question for you is: does [ä] = [ɑ̈] ? Do those modified-by-a-diacritic symbols represent the same thing, meeting as they might in the middle? To me, I've always assumed that [ä] is more front, while [ɑ̈] is more back, that they *don't* represent the middle of the bottom of the chart. But that's just my assumption. What's the convention? Or am I confusing [a̙] and [ɑ̘] with those centralized versions, which should really be in the centre?
Or should I say [a̠] and [ɑ̟]? (that's a minus under the first and a plus under the second, if they didn't make it through the email unscathed.) Can you help clarify? I bet other blog readers might like to know...
The 1989 IPA Convention in Kiel that I mentioned yesterday also attempted to clarify what was meant by “centralization”. There it was decided that the superposed umlaut means centralization in the sense of moving horizontally towards the centre line of the vowel diagram.
But the IPA never attempted to define how much centralization is involved. Common sense suggests that [ä] would generally be still somewhat front of the centre line, and [ɑ̈] somewhat back of it. They would straddle the proposed [A].
A new diacritic, the superposed small ×, was introduced to indicate a “mid-centralized” vowel, i.e. one that was modified towards [ə] — not only fronter/backer than implied by the base vowel, but also opener/closer. So the current official IPA doctrine is that [u] with the × diacritic means the same as [ʊ], whereas [ü] shows modification merely in the direction of [ʉ].
I have to say, however, that I have never seen this “mid-centralization” diacritic in actual use. Has anyone?
And I notice my browser won’t render it properly.