What CC0 samples/sounds do you use, if any?

Hello all! Long-time audiophile/composer here looking to get into game dev. I’m currently working on a project prototype where I need genuinely CC0/public domain audio (not just “royalty-free,” which usually still comes with its own restrictions). I’m building something that triggers individual samples directly rather than baking them into a finished mix, so I need sources with zero ambiguity on that front.

So far I’ve found Versilian Studios Chamber Orchestra Community Edition and (obviously) freesound.org.

What CC0 sources/samples do you rely on? And where’d you find them? Especially interested in anything choir/vocal, but happy to hear about anything good. Trying to build out a solid list for future projects too.

Thanks!