what the heck is Sufjan Stevens up to these days?

Yeah, thats an understatement. Neil Young knows the score.

Note the date

Kudos to @Neilyoung who requires a COVID test before his concert 👏🏻👏🏻 pic.twitter.com/8mIMzUDJsQ

— Dalia Hasan (@DaliaHasanMD) September 17, 2023

And KISS are using some kind of advanced UV based antiviral treatment before and after each show.

https://vancouversun.com/news/local-news/kiss-took-vancouver-firms-treatment-to-avoid-covid-and-cancelling-world-tour-manager

xp Well, this is the "Conclusion" of that Int'; Journal of Audiology report... just pointing it out

Ah, there's been a shit ton more research since then. Too much to link to, but this gives some indication.

https://www.google.com/search?q=covid+hearing+loss+tinnitus&oq=covid+hearing+loss+tinnitus