#Peertube accepts audio-only files in several different formats (.mp3, .ogg etc). You can pick an image (.jpg, .webp etc) to display while the audio plays.
And if you create a channel on Peertube for your audio files, you've effectively created a podcast that people can subscribe to. Just put the channel URL into the podcast app (at least that works for me in Antennapod on Android).
https://fedi.tips/how-to-publish-videos-and-audio-on-peertube/
