The present study aimed to investigate audiovisual segregation abilities in proficient and non-proficient CI users. Using a speechreading task and three types of auditory distractors, we showed that the presentation of auditory speech stimuli significantly impaired speechreading performance in proficient CI users, just like in NH participants, whereas speechreading performance was unaffected by auditory distractors in non-proficient CI users.
Traditionally, all CI users have been considered equal, and equally different from NH, in audiovisual tasks. In short, it is assumed that this population, although capable of normal integration, tends to rely more heavily on visual cues in conditions of incongruency (e.g. 
. However, recent evidence from our laboratories 
highlights the importance of CI proficiency in audiovisual interaction outcomes. We suggested that whereas CI users that were proficient at speech recognition could perform at normal-like levels, those that were not would favor visual cues and show anomalous audiovisual integration. The results presented here therefore support two notions: i
) that CI speech recognition proficiency is associated with audiovisual interaction outcomes in this population and ii
) that several CI users, namely the proficient ones, can show normal-like performance on an audiovisual task.
Cross-modal reorganization has been repeatedly shown to occur in the profoundly deaf (e.g. 
). In fact, in CI users, there is an activation of the early auditory cortex in the presence of visual stimuli and this activation is greater for those who show poor speech recognition abilities 
. In addition, CI users display atypical low-hierarchical visual activity during speech recognition tasks 
. This activity in the visual cortex is less marked and less consistent in naive than in rehabilitated CI users, suggesting that these visual cortex activations are due not only to deafness-induced plasticity, but also to brain reorganizations related to the functional learning of associations between visual cues and oral speech 
. Therefore, different levels of auditory-to-visual reorganization in cochlear implanted deaf subjects could explain the varying audiovisual segregation abilities reported in the present study: greater cross-modal reorganization would lead to the overuse of visual information and consequently to a greater capacity to ignore irrelevant auditory cues.
Some other issues, however, could also explain the pattern of results observed across tasks and groups. First, the three audiovisual tasks arguably did not require the exact same attentional resources. Indeed, speech stimuli were more salient and more complex than noise stimuli and consequently, were more likely to capture attention. Some studies, moreover, suggest that children with CI could perform poorly on attentional tasks 
, although performance might improve progressively with the use of a CI 
. In our study, putative impairments of visual or auditory attentional processes have unfortunately not been evaluated. These capacities might need to be investigated further in those populations to better understand their implications in the present results.
In conclusion, our results strongly suggest that in terms of audiovisual interactions, proficient and non-proficient CI users should not be lumped into a single group. More specifically, we show that normal-like audiovisual interactions are possible in proficient users and we show that CI proficiency is associated with audiovisual interactions in CI users. CI proficiency must therefore be taken into account in further studies of audiovisual interactions in this population.