Within the task-based language teaching approach, the effect of input characteristics has been more centered on written than on aural texts. Moreover, the interplay of input characteristics and individual differences (IDs) has been insufficiently investigated. The current study sets out to address these gaps by comparing L2 learners' comprehension of authentic and modified versions of two lectures and how IDs mediate the role of input condition in listening comprehension in an EAP context. The input was manipulated in terms of lexical sophistication and cohesion measures following previous research and informed by Natural Language Processing tools (e.g., Coh-Metrix, TAALES). Language aptitude, listening anxiety, task difficulty, task engagement, topic familiarity, and input condition (i.e., authentic and modified) were used as explanatory variables of listening comprehension as measured by 30 multiple-choice questions. The results of the Linear Mixed Effects Model suggested that the modified condition was significantly easier when IDs were controlled for, and engagement level and topic familiarity mediated the students' performance in the authentic and modified conditions. While high engagement and high topic familiarity were necessary for successful performance in the authentic condition, the opposite was true in the modified condition.