The recent AUE discussions about the pronunciation of the consonants in a word like "ditty" have led me to the tentative conclusion that I have no (d) in my speech.
{d} is defined by the International Phonetic Association to be a voiced alveolar plosive. (See
http://www2.arts.gla.ac.uk/IPA/pulmonic.html .)
Now "plosive" is a relative term. There are sounds, like the first "p" in "pop", that have an unmistakable expulsion of air when the stop is released. Then there is the pronunciation of my first "d" in "ditty": If there is a plosive present in that sound, it's so small as to be hardly noticeable, and it seems doubtful that the consonant should be called plosive.
It follows from that that I have no pronunciation of "d" that meets the IPA definition of (d), and that in turn implies that I have no (d) in my speech.
Whether either of the consonants in my "ditty" should be called a flap seems questionable. The New Shorter Oxford English Dictionary has the following relevant definition of "flap":
b Phonet. A consonantal sound produced by a single fast flapping motion of the tongue or other organ.
A very significant word there is "fast". When I pronounce the consonants in "ditty", I feel I'm pronouncing both of them with the same tongue activity. The tongue rises unhurriedly to my alveolar ridge, stopping the air flow, then releasing it. I'm not conscious of such a fast motion of the tongue as to warrant calling it a flap. And when the stop is released, I'm not conscious of the release of air being in the nature of an explosion. In contrast with that, when I pronounce a truly plosive consonant like the first "p" in "pop" or the first "t" in "top", I'm well aware of the sudden release of a significant amount of air.
This seems to be yet another case where there's no "it is or it isn't", but a continuum, here a continuum of plosives ranging from vanishingly small to substantial.
I believe that my plosive in the pronunciation of an initial "d" is near the vanishingly small end of that continuum, and so is best considered to be absent.
With the plosive absent, my "d" in initial position doesn't qualify as an IPA (d).
My pronunciation of "d" in an intervocalic position, like the second consonant in "ditty", consists of about the same unhurried tongue motion and air release that is found in the initial "d". So it can't be called (d) either, and it can't properly be said to be significantly different from my initial "d".
If I have a voiced alveolar plosive consonant in my speech, I can't think of a word that would convincingly illustrate it. Therefore, I feel led to conclude that I have no (d) in my speech.
In passing, and for what it's worth, I note with interest that the consonant chart of the IPA has no provision for an unvoiced alveolar flap.