As of today, my article with Carolyn Blume from TU Dortmund is available in the special issue of TESL-EJ on Global Englishes and translanguaging. It is open-access so it is available for free.
We used TED talks as online self-study, with one group watching talks by speakers of prestige varieties of English (so-called ‘native speakers’) and one group watching speakers outside of these prestige varieties.
The title says it all: there were no real differences between groups. Somewhat worryingly, neither group made gains in vowel learning, which was what we were intending they learned. Both were the same, although a limitation could be learners cramming at the last minute. However, this is something students do!
The article is here, and check out the whole of the special issue while you are there.