One way to meet the requirements for different locations would be to produce content which are designed to be usable with the audio alone (as a podcast), vision alone (as a slideshow), or both (as a vodcast). Long vodcasts could be divided into short chapters, of one to five minutes.
It would be possible to produce the versions of materials semi-automatically. As an example, I have produced a text-to-speech vodcast, and podcasts for the learning module "Reflective Learning". These have no structure, but the e-book they are derived from does. It would be possible to break the vodcasts and podcasts into chapters, based on the chapter and sub-chapter hierarchy of the e-book. As an example, the chapters of the e-book (indicated by HTML H2 markup) would give audio chapters of about ten minutes, suitable for walking students. Sub chapters (indicated by H3) would break the audio into two minute segments.
"In general, rich and long podcast is recommended while a student alone, even while walking, as we have seen in chapter four that Saudi students highly prefer to be engaged with m-learning while walking alone.
Students highly prefer vodcast and text respectively in busy contexts, so if possible providing slides synchronised with audio in a way that students can read the slide and opt to listen to their lecturer explanation for each slide.
Students highly prefer audio while walking alone, and this research show that Australian students prefer audio in all walking contexts. On the other hand, students dislike audio in quiet and busy contexts.
So, it is highly recommended to avoid disseminate audio podcasting in stationary context."
From Al Ismail, p. 131, 2018.
Al Ismail, Mazen Ibrahim I (2018-12-17). The impact of learners' characteristics on m-learning preferences, and how m-learning preferences form choices in different contexts. URL http://hdl.handle.net/1885/154711