Studies of second language speech perception can highlight the role of prior knowledge in native language processing. This study compared native and non-native identification of plosives in words spliced from natural utterances when presented in noise, with/without the context of preceding word. Both listener groups performed at the same level in the absence of context at high noise, suggesting that cues surviving energetic masking and splicing were similar for the two languages or that they had already been acquired by the non-native group. However, native listeners gained significantly more when contextual information in the preceding word was present, indicating that cross-word, extra-syllabic, cues are less easily exploited by non-native listeners. An acoustic analysis revealed subtle durational differences in the preceding word rhyme, knowledge of which may contribute to the native advantage. Other possible explanations for the native benefit from cross-word context are discussed.