There's portions where the voices overlapping is intentional, like calling into a party line on accident, and others where you can tell immediately from the Voice who is speaking. Few other authors have characters you can (or must) identify from idiolects alone.
There are glimmers of JR in Gaddis' earlier work The Recognitions, specifically during the party scenes where voices overlap. But of course because the rest of the book is written in a "usual manner", you can recognise who's saying what quite easily.
