LanesController.lanes explicitly sets lane.media after creating a new lane:

lane.media = [Edition.BOOK_MEDIUM]

This value incorrectly restricts the lane so that only ebooks are considered members of the lane. I don't know if this actually affects a patron's ability to see audiobooks in the lane, but I think it does, and it definitely affects the counts of items in the lane.

There's currently no reason for lane.media to ever be set, so the code can be removed.