Again, I’m no film student, don’t really know how to talk about sound, but in this case I was able to track down an archive on an ancient magazine article written by the sound designer, Alan Splet. In the article Splets discusses his experiences with Dune’s directer, David Lynch. Splet and Lynch new each other already, they worked together on the elephant man and had built up a working relationship. They were actually meeting to discuss ideas for the films sound production, months before the actual filming of Dune had begun. In fact Splets began work on sound production before even the first frame of film was exposed.
Splets goes on to say that around 90% of the sound in Dune was done off set, in post production. With the exception of dialog, almost no sounds that were recorded on set were used in the final product, not even foot steps. Splet remarks that Lnych felt that the sets sounded unrealistic.
Interestingly Splet began his work on the sound so early that he had completed two thirds of it before even saw any footage, apparently he was working purely from the script he was given and conversations with Lynch. He says he was guided by a sense of what Lynch was looking for and his own imagination. For Splet, Dune was a bit of a departure from the norm, he explains that was used to using stock sound effects from a library, whereas in this film, he used almost entirely new effects, he produced himself. Part of his reason for doing this was that he felt that since Dune takes place in a world far removed from our own then the sounds and music that we are used to would be inappropriate in context. So he endeavored to invent suitably bizarre, new sounds.
Here is a link to the full article: