There is a systematic relationship between stress accent and pronunciation variation in spontaneous American English discourse. Although all constituents of the syllable are affected by accent, its impact is particularly manifest in the nucleus and coda. For example, height of the vocalic nucleus is closely associated with accent weight, and deletion of coda and onset segments is far more common in unaccented syllables. Such patterns imply that stress accent and syllabic articulation are inextricably bound together, and this knowledge could be used to improve pronunciation models for speech applications.