A set of three perceptual experiments is described. These experiments were designed to provide identification scores on CV sequences for French. Original stimuli were augmented with acoustic "monsters" where burst were excised or replaced. The first identification task shows that information carried by vocalic transitions can be overwritten by burst information. The importance of this phenomenon is inversely proportional to vowel aperture. The second experiment shows that these results are almost insensitive to relative amplitudes between the burst and the vowel. In the third experiment we manipulated the voice onset time (VOT) of the monsters using high quality analysis-resynthesis. Stimuli with a very short VOT were perceived as bilabials but VOT manipulation did not affect the /t/-/k/ confusions. These experiments claim for a dynamic model of stop identification where burst and vocalic transitions both contribute and compete to the phonetic decision.