I was asked to help with a survey where participants basically answered questions like "Do you like this song?". It's easy, but the audio files were in MP3 and had to be converted to MP4 video having only sound. HTML has AUDIO-tag. Should we consider adding it to LimeSurvey?

audio tag didn't work in HTML editor or in santitizer ?

Sorry for being unclear. I didn't test writing raw html. I meant that there should be nothing very hard about adding audio to the html editor, just like it now have video.

But I am not sure if this would be usefull to others.

I guess a button for including MP3 / Audio files is as useful or not useful as a button to include videos.

I thought: This can't be that difficult, for sure there is an option in CK editor to add a button for MP3 files.

Either I am looking wrong, or there isn't:
ckeditor.com/docs/ckeditor5/latest/features/media-embed.html

Actually the web page about CKEditor does not say anything about videos. It contains info for embedding Youtube or similar, or uploading an image to own server, but not about uploading video.