This study examined how L2 listeners' proficiency levels interacted with the two major process-based listening instruction methods of (1) strategy training and (2) interactive training (which involved training in strategies and bottom-up skills), to influence the listeners' development. In a mixed-methods design, the quantitative component of the study reanalyzed data from an earlier study by the author which had compared these two instruction methods, with the current study factoring in the listeners' proficiency level. The less-proficient listeners (LPLs) were at lower-intermediate level, and the more-proficient listeners (MPLs) at intermediate level. Trends in the quantitative data showed that in the interactive course, the LPLs improved their listening comprehension more than the MPLs. By comparison, the strategy course learners at both these proficiency levels improved their listening comprehension to almost equal extent -- but slightly less so than the interactive course LPLs. Quantitative and qualitative analyses then highlighted the benefits derived by the interactive course LPLs from learning the bottom-up skills, especially connected speech and intonation skills. For the MPLs in that course, learning the bottom-up skills appeared to provide less value than learning the strategies. Implications of the study for listening instruction theory are discussed, with advice given for classroom practice.