Production planning and coronal stop deletion in spontaneous speech

Coronal stop deletion in English word-final consonant clusters (CSD), one of the most studied variables in sociolinguistics, has been consistently shown to be affected by the preceding and following phonological context. Previous work has treated a following pause as one type of context, on par with a following consonant or vowel. Looking at deletion rates in a corpus of spontaneous speech, we instead treat pause as a quantitative proxy for boundary strength and test the hypothesis that, not only does pause by itself gradiently reduce deletion rate, but also modulates the effect of a following phonological segment, as predicted if phonological processes are constrained by the locality of production planning. We show that the influence of a following segment on CSD decreases with increasing boundary strength, but not that of a preceding segment: an asymmetry that provides direct support for the production planning locality hypothesis.