Los Angeles - Christopher Nolan may have to change the sound mix of The Dark Knight Rises.
Studio Warner Bros is said to be concerned after online reaction to the first trailer of the highly-anticipated film noted it was difficult to understand villain Bane - played by Tom Hardy.
The character draws super-human strength from a drug which he must constantly inhale, meaning his mouth is covered in the movie.
Drawn the line
Websites including IO9 and What Would Tyler Durden Do, as well as fans on Twitter, have noted the problem, and the studio has spoken to the filmmaker to ask him to make changes.
However, he has drawn the line at a complete re-working.
A source told the Hollywood Reporter: "Chris wants the audience to catch up and participate rather than push everything at them. He doesn't dumb things down. You've got to pedal faster to keep up."
The movie - which stars Christian Bale as Batman for the third time and Anne Hathaway as Catwoman - is still in the editing process, and is due for release in July 2012.