For various reasons, bringing narration into an animated film causes plenty of headaches when it comes to international distribution. Simply writing the narration has its own particular problems and calls for close collaboration with the writers to synchronize the words with the idea, images and timing.
For The Man Who Planted Trees, translating the narration and recording the voice—over were both fraught with difficulties; but in this case, the storyline was the film's backbone. It structured the sequences and inspired the images and sound-but without necessitating a strict match.
Frédéric Back with Philippe Noiret, Hubert Tison and Maurice Dubois, 1986.
The opposite was true for The Mighty River, where it was the images that guided both the narration and the sound effects. In this case, since images alone could not convey the complex realities of the St. Lawrence River, there was no way to avoid adding verbal explanations. Images and words had to work together. The human voice also creates a relationship with the audience that is not always possible to achieve through sound and music alone.