[crazygringo]

Acoustics are modified in extremely non-linear ways depending on the shape of the room, bodies within it, materials, acoustic reflection, acting differently at different frequencies, and so on.

In theory if the entire 3D layout and material properties were known known in advance you could get clear audio analytically. But reverse-engineering the 3D layout and materials from existing audio is essentially impossible.

So machine learning is used to find approximate solutions that work.