This research attempts to define the temporal extent of anticipatory labial coarticulation and the effect on rounding onset of a stressed nonround vowel located temporally prior to the rounded vowel. The results suggest that the onset of the labial rounding gesture is controlled in relation to the temporal extent of the nonlabial duration preceding the rounded vowel and that the onset of activity for the rounded vowel is somehow related to the stress of the preceding nonround vowel. These results argue against the classic articulatory syllable model as well as against a concept of the onset of rounding being temporally locked to the rounded vowel. They can be argued to support a look-ahead or scanning model.