The deletion of word-internal alveolar stops in spontaneous English
speech is a variation phenomenon that has not previously been
investigated. This study quantifies internal deletion statistically using
a range of linguistic and extra-linguistic variables, and interprets the
results within a model of speech production. Effects were found for speech
rate and fluency, word form and word predictability, prominence, and
aspects of the local phonological context. Results of the study are
compared to results from the numerous studies of word-final alveolar stop
deletion, internal deletion in laboratory speech, and also to another
internal alveolar stop process, flapping. Our findings suggest that
word-internal alveolar stop deletion is not a unitary phenomenon, but two
different processes that arise at different points during speech
production. In syllable codas, deletion results from cluster
simplification to achieve gestural economy and is introduced during
segment planning. In syllable onsets, deletion is one outcome of gradient
lenition that results from gestural reduction during articulation.The research reported here was supported by
NIDCD grant DC004330 to Mark Pitt, Keith Johnson, and Elizabeth Hume. Our
thanks to Mark Pitt, Keith Johnson, William Labov, David Sankoff, two
anonymous reviewers, and numerous participants of NWAV02 for useful
comments and constructive feedback that helped us develop the
article.