I know! The whispering!

It was a bit.. melodramatic, but it was Lynch's solution to a chief component to the books it was based on.

Dialogue in the books were intertwined with thoughts. You were told what the characters were thinking and some of the main characters communicated telepathically.

In hind-sight, I can't think of any workable alternative to the whispering outside of drastic rewriting.

I think the bigger problem was the action. The sets, costumes, and music were all bigger than the action. If the warriors & weapons only fought as great as they looked, the movie would have gone down in top sci-fi of all time. The lasers looked and sounded bad, bad, bad.