Bob Kennedy raised some interesting points about the trajectory of the initial vowel in "Mike", "Diane" etc. — let’s call it long i for ease of reference, since the appropriate IPA values are part of what’s at issue.
Bob suggested that
it’s almost always central rather than back. The only dialect I know of with a nucleus both low and back is Surfer Dude (which I’d link if I could find a clip – think Spicoli in Fast Times at Ridgemont High) and islander dialects like Martha’s Vineyard, Okrakoke, or (probably some varieties in) Newfoundland. Many of these will have a variant more like [ɔj]*, where the nucleus is back but not low. I’m sure I’ve also heard [æj] (with a front nucleus) from Southerners when not monophthongizing, as well as [ɛj] (fronted and raised!) from some Canadians.
In my own speech , I have two variants of long i — one longer, lower and backer, the other shorter, fronter and higher.
This is because I have a clear vowel quality distinction between writer and rider — or fife and. five. I’m not sure where this came from, since I grew up in eastern Connecticut among Yankees. I haven’t checked with others from my home town, but nobody ever commented on this feature in my speech, anyhow.
The nucleus of the longer/lower/backer one is about as back as any of my low vowels get. and the shorter/fronter/higher one starts out nearly as far back, but just moves forward faster. Here’s a quick formant plot (single measurements of artificial productions, so the usual caveats apply):
The points labelled with numbers are my attempts to produce steady-state vowels approximating those in
The red X’s mark the trajectory of long i in five, while the blue O’s mark the trajectory of long i in fife.
Looking at student formant plots in phonetics-class exercises over the years, I haven’t seen this distinction very often, but (as I recall) many of the Americans have had long i trajectories rather like my lower/backer one. So I don’t think that low back nuclei are as rare in long i as Bob suggests, though I agree that low central ones are common too. American English low vowels are so cramped in the front-back dimension — even more than the necessary narrowing of the vowel quadrilateral, I think — that I find it hard to place examples accurately just by listening, and I haven’t seen a systematic instrumental survey. In general, there seems to be much less good instrumental data about diphthong trajectories than about other aspects of dialect variation in English.
I agree with Bob that there are some southerners who sometimes seem to have an æ-like nucleus in words like "high", but I’ve never gotten a recording of this. Can anyone supply one?
None of this excuses the Nature reporter, who remains on the hook for a remedial course or two, if he’s going to continue on the speech and language beat.