Although researchers have indicated that speech production is an important aspect of academic success and acculturation (e.g., Berman & Cheng, 2001; Cheng & Fox, 2008) and teachers have identified the need for more preparation in this area (Thornbury, 2005), there is still a lack of time and practice devoted to the speech issues of international students in English for Academic Purposes (EAP) courses at the tertiary level (Maleki & Zangani, 2007; Wood, 2010; 2015). Many second language (L2) learners in academic programs have expressed frustration with the difficulty their listeners often have in comprehending what they say (Derwing & Munro, 2015). To address this instructional gap, an electronic portfolio (ePortfolio) learning module designed to guide learners to work more autonomously was integrated into EAP courses at a medium sized university. Learners were encouraged to engage in more autonomous learning (Reinders, 2011) by examining their performance, planning interventions, reviewing performance, and assessing improvement. This study examined the impact of the ePortfolio learning module on 55 participants in developing speech comprehensibility and autonomous learning by applying a two-phased mixed methods explanatory sequential design (Creswell, 2015). In Phase I, quantitative data were collected through the use of a survey and a pre- and post-treatment test. In Phase II, qualitative data (18 participant reflections, four semi-structured interviews) were analyzed. Findings of the first phase indicated that speech comprehensibility improved through better learner management of volume or degree of loudness, speed, articulation, and word attack skills, and the lower the initial level of comprehensibility, the greater the improvement. Findings from the second phase indicated that over 90% of participants' comments were related to autonomous learning activities and that the more they engaged in autonomous learning, the greater the improvement in speech comprehensibility. Further, participants who improved the most were those who also applied the autonomous learning skills to other academic contexts. These findings suggest that the ePortfolio learning module was successful in filling the gap between the perceived need of L2 participants for support in developing speech comprehensibility and the limited amount of time available in the curriculum to address this need.