How did the sound of violence get from the thwack of Horse Feathers to the squishes of Vampires and Drive? The language of sound evolves, says Berger, as each editor pushes against the boundaries of convention and cliché. In orchestrating violence for a film like Apocalypse Now, or The Godfather 2, he might have cut eight different versions of each bloody sequence, at varying degrees of intensity. Then he'd work with the director to decide which version would take them to the edge of what's expected or acceptable without tipping into exploitation or schlock.
A few films have changed the language more explicitly. To construct the punching sounds for Raging Bull (1980), supervising sound editor Frank Warner started with a standard side of beef, but layered in bits of manipulated music, roaring animals, jet engines, and flashbulbs to create a brittle, electric, and wheezy mix of sounds that's unique to the film. (Even so, The Empire Strikes Back won the Oscar for sound that year.)
There's nothing quite so avant-garde in the elevator scene from Drive, but Bender and Ennis have made their own more subtle additions to the vocabulary of concussive violence. To depict the crushing of the skull, they used the slowed-down noise of cracking nuts; for the blood they recorded the sloshing of a viscous liquid. But to complement these "obvious" sounds, as he calls them—the squishing and gushing and head-crunching—Bender and his colleagues added another track, of Ryan Gosling breathing and snorting and firing spittle. Not every viewer will be aware of this additional noise, but it adds ferocity and intimacy to the scene. "We tried to create the personal experience of [killing someone], of going through the effort of doing it," says Bender.
The elevator sequence benefits from another trick of sound editing, in which a flash of quiet sets up an outburst of audible violence. In this promotional video clip, Bender explains how he removed the elevator noise in the moments before the action begins. It's another technique that was pushed to the limit in Raging Bull, where, in the instant before Sugar Ray Robinson unleashes on Jake LaMotta, there's only a faint rumble on the soundtrack. But continuing advances in theatrical sound systems since the mid-1970s have made the contrast between silence and violence greater than ever before, by eliminating any last vestiges of hiss and distortion. It's now possible to suck the audio right out of a theater, leaving members of the audience in a true stillness.
Better speakers and innovative sound design can certainly make on-screen violence more intense and affecting—but always at the risk of going too far. Consider the curb-stomping scene from American History X (1998). Supervising sound editor Frederick Howard overloads the violence with the amplified sound of the victim's teeth scraping and clattering against concrete. It's like nails on a chalkboard, and then the stomp plays out in a muffled crunch. That moment, once commended by critics as a bit of "horrifying gusto," now feels gratuitous.
Lon Bender knows the dangers of overselling the violence. For the original version of Braveheart, Bender and his colleague Per Hallberg illustrated the climactic disembowelment and beheading with the sounds of metal scraping on bones and sloshing blood. But after some people walked out of a preview screening at that moment, Bender and Hallberg stripped out the noise in favor of James Horner's orchestral score. The film went on to win an Oscar for best sound editing. (Horner got an Oscar, too.)
We might wish that the director and film editor of Drive had shown similar restraint. If there's one moment in the elevator that does bludgeon one's sensibility—and risks losing a visceral effect in actual, on-screen viscera—it's the 14th stomp in the sequence. We've already heard the thud turn into a crunch on its way to a squish. But the film won't let the brilliant sound editing carry the scene. Instead, we see a close-up of the cadaver's face, all caved in with a foot in the middle. Thud, crunch, squish. Wasn't that enough?