Second language (L2) listening requires efficient processing of continuing incoming information (Vandergrift & Goh, 2012). Even so, research into individual differences in L2 listening has mostly shed light on the role of linguistic knowledge measured without time pressure (e.g., Mecarty, 2000; Wang & Treffers-Daller, 2017; cf. Vafaee & Suzuki, 2020), leaving the role of processing speed and automaticity largely unexplored. To close this gap, we explored the determinants of successful listening using three processing tasks at lexical, syntactic, and propositional levels. Participants were 44 Chinese learners of English. Response accuracy afforded measures of vocabulary size, syntactic parsing skills, and formulation of propositional meaning. Reaction times and the coefficient of variation (Segalowitz & Segalowitz, 1993) afforded processing speed and automaticity measures at each level. We found a hierarchical relationship between different levels of processing, whereby lower-level, lexical effects cascade up and are mediated by propositional comprehension in accounting for listening comprehension. The results highlight the importance of considering processing accuracy and speed at different levels of the linguistic hierarchy to explain variability among L2 listeners. Different from most previous studies, we argue for a need to consider the temporal aspects of processing, along with linguistic knowledge, in modeling L2 listening.