https://archive.org/details/airchecks-formatswitches
This is a big nonprofit doing some legitimately amazing work cataloguing media. These are the kinds of people that treat things like valuable museum pieces, not just throwaway sound clips. I mean, it's never guaranteed that things in the Internet Archive stay in the Internet Archive (just this week, they lost a lawsuit and it looks like a lot of their catalogued books do not get to stay) but I think in this case, we're good. That audio is enshrined. Not exactly the Library of Congress, but not bad. For something that we're all nerds for! Whaddya know?!

Here's a choice one that has already made its official appearance in this august hall of audio: the end of 89X. (As anticlimactic as it was.) As well as the end of the River! (Even MORE anticlimactic.) I mean, I still love the preservation of it, even if it left a lot to be desired. SMH... stations can't even be bothered to tease a new format anymore. https://archive.org/details/89xand939th ... +River.mp3