A Phonetically-Based Optimality Theoretic Account of Consonant ...

In Figure 5c, the cavity sealed at constriction points A and B expands due to tongue
retraction during the articulation of a flanking front-back vowel sequence. As a
consequence, the enclosed air column rarifies, resulting in a decrease in PA. The reduced
volume between Band C will see a faster pressure increase than would be expected from
glottal air flow alone, due to the cavity compression resulting from tongue retraction.
Although I have only considered the oral pressure dynamics during labial and velar
constrictions, the discussions above on multiple supralaryngeal constrictions may be
extended to cover the alveolar place of articulation at constriction point B (or A).
There exist two more relevant factors to be considered: nasal opening and voicing.
Although the above discussions have assumed a raised velum (i.e., no nasal leakage) and a
spread glottis (i.e., considerable glottal flow) as the conditions during glottal flow, similar
oral pressure consequences can be assumed during voicing (low glottal flow) and
nasalization (lowered velum). However, both conditions will result in a slower
supralaryngeal pressure build-up: Voicing means a dramatically reduced rate of air flowing
into the oral cavity; nasalization has the same effect of reducing the net flow into the oral
cavity, by the nasal vent. Less flow will result in a slower pressure build-up.
4.3.2 Silverman & Jun (1994)
Silverman and Jun (1994) showed that oral pressure (henceforth Po) measurements
taken behind the lips during unreduced labial+velar stop sequences may serve as good
diagnostics for gestural overlap when the consonant sequence is flanked by vowels of
varying backness, and that the presence or absence of overlap is especially clear when the
vowel environment is front-back. In ipku, an overlapped sequence will show a positive­
then-negative change in Po (Figure 4a - Figure 5c - Figure 4b); in ikpu, an overlapped
sequence will show a negative-then-positive change in Po (Figure 4b - Figure 5c - Figure
4a). In both cases, the positive change in Po is the result of pressure building up behind
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