Yes, Chip, it is a by-product of Compressor surge, but I still don't see that the 2 are related.

They are both caused by air backing up onto the Compressor Blades. In the case of what I refer to as Turbo Chatter, the cause of the 'back-up' is the Throttle slamming shut, whereas with Compressor Surge it is a restriction in the system causing the air entering the engine to exceed the air that can get out of the engine.

Anyway, less of the physics and back on topic!!