It (sound) should strive to create a purposeful and fruitful tension between what is on the screen and what is kindled in the mind of the audience. The danger of present- day cinema is that it can suffocate its subjects by its very ability to represent them: it doesn’t possess the built-in escape valves of ambiguity that painting, music, literature, radio drama and black-and-white silent film automatically have simply by virtue of their sensory incompleteness — an incompleteness that engages the imagination of the viewer as compensation for what is only evoked by the artist.” – Walter Murch