d. Aspiration Voiced stops (in English) are never aspirated.
Voiceless stops are sometimes aspirated and sometimes not. These
voiceless stops will be aspirated: a. Word-initial, regardless of
stress: tap, cat, Topeka (stop precedes an unstressed vowel),
command (ditto) b. Intervocalic (between 2 vowels) but only when
preceding a stressed vowel. meticulous, repair, recalcitrant,
return
Slide 3
These voiceless stops will be unaspirated: a. Following /s/
stop, skate, stick, stare, spike b. Intervocalic, preceding an
unstressed vowel napping, camper, sicken, supper, thirsty (Note:
Sometimes these are unaspirated, sometimes they are lightly
aspirated.) See Table 5-2 (p. 96) of MacKay for a nice summary with
examples.
Slide 4
Voice Onset Time (VOT) VOT = Interval between articulatory
release and onset of voicing. voicing onset release voicing onset
and release ~ simultaneous VOT ~0 ms VOT ~85 ms
Slide 5
Voice Onset Time (VOT) voicing onset release Very short delay
between release and voicing onset (~10 ms) VOT ~10 ms VOT ~85
ms