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Abstract:
This study explores the control of the oral closure in stop
consonants where theduration of the oral closure differs for
linguistic purposes, using phonologically long and short stops in
Swedish. Previous work on labial stop has shown that the lips are
moving at almost their peak velocities at the instant of oral
closure. For stops produced with the tongue, previous work has
shown that the tongue movement velocity can be high at the
instant of oral closure. The tongue continues to move during the
closure, with larger movements of the tongue body for velar stops
than of the tongue tip for alveolar stops. When the closure
duration has to vary over a wider range, we predict that one way
a speaker controls the duration of the oral closure for a labial
stop is by varying the lip closing and opening movements. In
particular, we expect that the lower lip will reach a higher
vertical position for a long than for a short stop. Such a
strategy will result in the lips maintaining contact for a longer
period of time. For stops produced with the tongue, we don t
expect the tongue to actually stop during the closure for a long
stop. Rather, we assume that the magnitude of the movement during
the closure will be the same, or possibly slightly longer for a
long than for a short stop. This follows from the fact that the
tongue always seems to move during the stop closure, but it
cannot move indefinitely during the closure and also maintain an
air tight seal. Articulatory movements were recorded using a
magnetometer system. The results showed that the lower lip
reached a higher vertical position during the oral closure for
the long than for short stops. In addition, the lower lip
vertical velocity at oral closure was higher for long than for
short stops. The upper lip movement kinematics did not vary
systematically with closure duration. For stops produced with the
tongue, the movement trajectory of the tongue body and tongue tip
during the closure increased with closure duration for velar and
alveolar stops, respectively.
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