The aim of this paper is to investigate the influence of a prior knowledge of the vocalic context on stop burst perception. A previous experiment [2], during which the listeners were unaware of the identity of the following vowel, showed that bursts provided very reliable information about stop place but also that the performance variation significantly depended on the syllable and on the following vowel. We used fixed-length burst stimuli of approximately 25 ms in which all traces of vocalic segment have been set off. We report another experiment concerning the perception of the same stimuli but during which the identity of the following vowel was specified to the subjects. Results showed that the specification of the vowel identity led to a slight but statistically significant improvement in stop recognition. Nevertheless, the effects of this knowledge were selective and varied with the context.