The audio consists of two parts: the wonderful minimalist score by Vangelis, and sound effects that include distant booms, twinkling computer notes, dripping rain, strange languages, the whoosh of futuristic vehicles, even small details such as the crosswalk warning. Along with the set design, photography, special effects, acting, and other visual elements, the audio effectively immerses viewers into this incredible world and story.
Keep in mind that a typical viewer entering the local cineplex in 1982 to watch Blade Runner might have just stepped out of a Chevy Nova with an 8-track cassette player loaded with Juice Newton and Kool & The Gang. The visuals, the score, the sound effects, and the story would have been completely novel, and totally mind-blowing.
It's another of those movies which uses light extremely effectively, also.
In fact I've heard it said that every single shot in Blade Runner carefully deals with light specifically.
They may have a global tour of it in some places this fall.
The first theatrical release had a drab narration by Harrison Ford. At places it makes it sound like a cheap film noir detective story.
The Directors Cut is the unbutchered version.
Maybe 4D chess by Ridley Scott. Most had seen the optimized version first and was prepared for the magic which is the recut version ;-)
I have the opposite feeling with Apocalypse Now. The Redux version killed the pacing and explained too much. The added scenes are by themselves worthwhile (and explains later actions) but makes the complete movie a bit heavy handed.
By comparison Blade Runner feels more ethereal even though the both cover dark subjects of human nature.
I think Blade Runner stands out for the visual effects though. The dystopian future cities were great. It were these effects packed into a storyline why I did not want to watch the "sequel".