Image and sound must not support each other, but must work each in turn through a sort of relay

If a sound is the obligatory complement of an image, give preponderance either to the sound, or the image. If equal, they damage or kill each other, as we say of colours.

I always thought the sound and image of a movie was equal, played together. Reading this surprised me as I started to watch films differently. I now realize that one cannot enjoy both at the same time, it would ruin it all together.

A beautiful picture must be supported by a more quiet background sound or we would be distracted from the scene. Same goes for the opposite, When watching a less intense scene, there must be a more distinct sound to keep the viewers focus. Take example of a horror movie with poor sound effects, the viewer will quickly get bored and disinterested, on the other hand when watching something beautiful and colourful such as a scene shot of a scenery the viewer will invest their concentration in what they can see, therefore must not be distracted by the sound.

Sight and hearing. In Bresson, R. Notes on the cinematographer, (p. 50-52). London: Quartet, 1986.