Models of speech perception attribute a different role to contextual information in the processing of assimilated speech. The present study examined perceptual processing of regressive voice assimilation in French. This phonological variation is asymmetric in that assimilation is partial for voiced stops and near-complete for voiceless stops. Two auditory- visual cross-modal form priming experiments were used to examine perceptual compensation for assimilation in French words with voiceless versus voiced stop offsets. The results show that, for the former segments, assimilating context enhances underlying form recovery, whereas it does not for the latter. These results suggest that two sources of information -- contextual information, and bottom-up information from the assimilated forms themselves -- are complementary and both come into play during the processing of fully or partially assimilated word forms.