Word-internal /t,d/ deletion in spontaneous speech: Modeling the effects of extra-linguistic, lexical, and phonological factors

Abstract

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.