` :::Well, Kenyon in American Pronunciation (a different book) says, ``In south England, and often in America, this vowel [i.e. o] is a diphthong``. I think for most Americans it depends what kind of syllable it's in; it tends to be more diphthongal in open syllables and more monophthongal in closed syllables. I remember that in my first year of graduate school, after four years of undergraduate linguistics classes in which it was imprinted upon me that the GOAT vowel is a diphthong, it came as a great shock to me to see spectrograms of myself saying the words ``hayed`` and ``hoed`` and seeing no movement whatever in the formants. Up till that point, I had firmly believed I used diphthongs, because all relevant professors told me I did; but the spectrograms told me I used monophthongs. + `