Is there a publicly available dataset of spoken language for L2 acquisition? I would prefer children learning an L2, but any age range is fine. It would be great, but not necessary, to have speaking samples for each speaker in their L1 as well as L2.
learners corpus into the search slit of the Virtual language observatory (VLO) and you will find a plethora of resources.
CHILDES Transcripts and Media is a database for records of children acquiring languages, including both transcripts and audio/video files.
I'm not sure though if there is something on second language acquisition, at least they have media for bilingual children. Maybe that helps too.