On Fri, 8 Nov 2002 09:21:06 -0600, "Patrick C. Ryan"
>Speaking only for American English, of which I am a native speaker,
>both initial and final /d/ are voiced in all dialects known to me.
>Where did you get such information?
It's a well known fact (it applies of course not only to /d/, but to
/b/ and /g/ as well), and you can easily verify this for yourself.
During the closure of /b/, /d/, /g/ in absolute initial or absolute
final position (i.e. when preceded or followed by voicelessness),
there is no vibration of the vocal chords at all. In initial
position, the difference between /dV-/ and /tV-/ is of voice onset
time: for /dV-/, voicing (vocal chord vibrations) starts immediately
after the consonant, and the vowel is fully voiced ([tV-]). For
/tV-/, the initial part of the vowel is voiceless (/h/), and voicing
starts later ([thV-)]. In final position, the difference between
/-Vt/ and /-Vd/ is mainly vowel length: /-Vt/ is realized as [-Vt_]
([t_] = unexploded stop), sometimes with preglottalization [-V?t_], or
in certain British variants with aspiration/affrication [-Vth] /
[-Vts], whereas /-Vd/ is [-V:t_], with lengthened vowel.
I'm not making this up. Consult any English phonetics manual (e.g.
Ladefoged "A Course in Phonetics", 3rd.ed., chapter 3 "The Consonants
of English", p. 50, sample quote: "Most speakers of American English
have no voicing during the closure of so-called voiced stops in
sentence initial position").
Miguel Carrasquer Vidal