In Michael Ondaatje’s book The Conversations: Walter Murch and the Art of Editing Film, the editor and sound designer of many Francis Ford Coppola films emerges as a true innovator and a boundlessly creative manipulator of the basic elements of film: image and sound. Murch is also uncommonly self-reflexive and shows a deep understanding for the perceptual effects that his work has on an audience. Through his art and his craft, he places viewers in the heart of battle in Apocalypse Now or firmly inside the minds of characters like Michael Corleone and Harry Caul. But Murch isn’t content with simply presenting concepts and techniques, fully-formed, to the audience. Instead, he lobbies for the creative input of everyone involved in the process of making a film, a process, Murch believes, that ends not with the final mix of a film, but with its eventual interaction with an audience. Through the course of his conversations with Ondaatje, Murch argues that the great films always leave the hardest work to the audience, the task of synthesis, of perceiving new worlds, magically emerging from nothing more than a collection of discrete sounds and images.

Murch firmly believes in the active role the audience plays in interacting with a film, even describing it as the final step of making a movie, completing the other stages of scripting, photography, editing and sound mixing. Yet Murch also describes film as “omnivorous” and indeed much of The Conversations is dedicated to exploring the ways in which editors and sound mixers are able to manipulate audience’s perception. In watching a film, the viewer does not “[bring] along his own images,” the filmmakers select them. How, then, does this “omnivorous” medium allow for a constructive dialogue with the audience? How can filmmakers use images and sound in creative ways to open up a film, to create a space for the audience to participate in its creation?

In many ways, Murch’s career has been dedicated to finding the answers to these questions, and he has certainly discovered a great many creative ways to manipulate perspective and allow the viewer to actively create the space of a film. Take, for example, Murch’s efforts to suggest the aural space of a highway toll booth in Coppola’s The Rain People. First, Murch tried simply adding the sounds of car traffic directly, but the noise overwhelmed the scene’s dialogue. Not wanting to abandon the idea of grounding the action within a very specific perspective, he discovered that the inclusion of one key sound, a wrench being dropped fifty feet away, “was able to bring along with it, imaginatively, all the traffic.”

Similarly, in THX 1138 the sounds of crowds of people walking were not enough to convey the chaos just outside the futuristic city walls. It sounded too flat. But the addition of strange grunting gave the sound the “edges” it needed to crystallize the effect of a large crowd. These examples prove, contrary to film’s “omnivorous” nature, that audiences do indeed actively participate with the perception of a film, constantly working to synthesize the various elements the filmmakers give them. The sound of the wrench in The Rain People activates the audience’s imagination, unconsciously, and calls upon them to create the location of the highway toll booth in their minds, to process and then expand upon the sounds that Murch provides.

The “spaces” audiences are called upon to create need not be literal. By emphasizing unrealistic or metaphorical sounds, a sound mixer can suggest not just locations, but the frame of mind of his characters. In Apocalypse Now, for example, Murch famously used electronic helicopter blades and effects like an artificial chorus of crickets. Though these sounds are artificial, they are as a result even truer to the distorted psychedelic head space of Willard and the film as a whole. In The Conversation, Harry Caul plays a recording again and again looking for clues to a murder. The final time the recording is played, Murch slyly uses a different reading of a key line to illustrate how Harry’s perspective his fundamentally changed. It’s these examples of creating not just real perception, but hyperreal perception, that almost paradoxically allow the audience to help create the world of a film.

The principal uniting Murch’s work in both film editing and sound mixing is context. It’s only through the context of the building blocks of film, sound and image, creatively placed together in harmony or contradiction, that an audience can actively participate, helping the filmmakers create new modes of perception through cinema.