"WHAT YOU MAY NOT HAVE KNOWN: The 1989 laserdisc was quietly reissued with the newly corrected letterboxed transfer, completely doing away with the "incredible shrinking ratio" problem. This release, pressed by Mitsubishi Japan, features the same catalog number as the 1989 release. So how can you tell the two apart? This corrected edition is released by "Fox Video." Coupled with the 1985 audio mix , this could very well likely be the best presentation of the film
And in the 1985 audio mix...
"effects, new stereo'd effects (Jawa voices after Artoo's capture) and, most noticeably, the addition of C-3PO's line in the Death Star ("The tractor beam is coupled to the main reactor in seven locations. A power loss at one of the terminals will allow the ship to leave"). This new sound mix was used for every subsequent video release until the 1993 THX "Definitive Collection" remastering." Davis DVD Video Timeline
Actually, it sounds a little out of place. It was definitely recorded at a different time.