In our production we also review voice recorded scripts and other audio files.

It is weird that audio files are not supported, since a normal web browser knows how to play them. Since Audio notes are in your roadmap, we hope general audio upload would also be supported.

For our needs it would be already ok, if the transcoding would use something like ffmpeg to convert the audio file to a video file with no video or a default placeholder image over the whole duration. That is currently our workaround when reviewing such files in syncsketch.