This study explored actualization of affordances of audiobooks for mobile learning, as well as constraints encountered by students engaging with elective readings in a university course. Participants often tried learning in different situations before settling on a preferred learning practice. Students reported having listened on-the-go as well as in their traditional learning spaces. Some students took advantage of hands-free, eyes-free and screen-free listening along another task, such as a commute, note-taking or a sport activity. Participants also leveraged audiobooks for incidental and intentional learning of second language (L2). Co-listening was identified as an affordance stemming from unique properties of audiobooks and students' initiative. Some students combined listening and reading to address challenges related to mLearning in L2. Despite having had little or no prior experience of learning with audiobooks, most participants discovered new ways to learn -- using audiobooks to customize their mobile learning practice.