R2D2: The OT deleted scenes are muted from time to time without any technical reason. Sound is suddenly off completely in the middle of a shot and on after a few seconds again in the same shot.
Some of the scene have the director (Kershner) making stage comments, if these clips got to a second level of editing, those would have been removed so the sound crew would begin to figure out how to patch or redub. That might explain for the cut outs.