Audio and transcripts. Which could have been amended to the existing NIP or added as a second event. That's how @fiatjaf and I plan on doing it. That was devs and users have choice. Now we have two audio NIPs that aren't compatible. It's like making a new NIP for pictures with a new tag when we already have kind:20.

Who does the transcription on Airchat? It's really weird to make a client requirement to publish the audio together with the transcript. What if I can't provide a transcription? Maybe I'll just leave it blank then? What if my transcription quality is awful?