Ever since I saw the first videos of gameplay from KSP 2 I noticed how much better the sound design is in it, and I felt like that is a huge missing thing of KSP 1. I'm not sure if I'm just unaware but I can count one mod that tries to take care of that, it would be Rocket Sound Enhancement, but as of now that mod has some SERIOUS performance issues and I would consider it a very demanding mod for how little it gives back, I remember I constantly crashed while using it so that's out the window for me.
I think just replacing the sounds would be easier rather than trying to make an entire new sound physics system, isn't that what they did in KSP 2 anyway?