@NEETzsche it's in changelog:

## [2.0.2] - 2020-04-08
### Added
- Support for Funkwhale's `Audio` activity

There are several tests that explicitly verify that Pleroma ingests funkwhale's Audio documents

https://git.pleroma.social/search?search=funkwhale&nav_source=navbar&project_id=2&group_id=3&search_code=true&repository_ref=develop

Best i can tell it stores several activitypub types and puts them in timeline. I haven't seen any funkwhale audios in-wild but at very least i have experience federating with peertube from pleroma - from Pleroma User's point of view it looks like a normal "post" with video as attachment, so from what i see in the OG MR it works the same for Audio.

https://git.pleroma.social/pleroma/pleroma/-/merge_requests/2287

My brain is 99% fried from disasterous day so please excuse me if i'm not making any sense and skipping words.

Long story short - Pleroma understands Peertube Videos and Funkwhale Audios and displays them as regular "posts" with given url as attachment.

Us sending out "Listen" for a made-up "Audio" is inconsistent with this behavior so say the least.