Nicolas Titeux

Sound designer | Sound mixer
Composer

The 7 tricks of sound in movies

by | 21 April 2020

Sound in movies is sometimes far from reality to better entertain us. Here are some tricks that spectators, accustomed to cinematographic language, don’t not always notice.

1 The speed of sound

 
In movies, sound effects are always synchronized with images. Quite normal, you may think?

This is to forget that the speed of light is a million times greater than the speed of sound. We hear sounds with delay when we are far enough from their source. This allows to count several seconds before hearing the sound of a lightning bolt.

When you attend fireworks, even at the front row, you always notice that the sound comes after the explosion.

In The Fellowship of the Ring, as in most films, sound propagates at the speed of light.

2 The sound in space

 
It is a well known fact: in space, as there is no air, sound does not propagate. However, most movies pretend it does.

Only a few recent productions like Gravity adopt a more realistic vision of sound in space, by making the subjective sound of the characters heard inside their spacesuit.

In Armaggedon, no realism at all. Asteroids whistle and rip the air … in space.

3 Hearing inaudible sounds

 
Have you ever chatted with someone in a nightclub? Generally, you are forced to shout in the ear of your interlocutor who barely understands one word out of two.

In this scene of Matrix, no problem. Despite the loud music, the characters talk from a distance of one meter, without straining their voices. Neo even hears the delicate steps of Trinity approaching.

4 Non-existing sounds

 
To give a danger feeling to a laser beam, nothing beats a good shrill sound, like in Goldfinger .

Obviously, a laser produces no sound. Except maybe if it has a vibrating transformer or a fan to cool it.

5 Overkill

 
UI sounds (electronic sounds emitted by machines) are a classic of science fiction. Although they exist in reality, they are overused in cinema to reinforce the futuristic or technological feeling of a device.

In this Alien scene, the keyboard and screen display generate a lot of beeps. In reality, who would bear to work with such a noisy computer?

On a different register, a sword that resonates with a beautiful metallic sound is perceived as sharp and very solid.

This sequence from Troy is full of swords that scrape and resonate… sometimes even without being touched.

6 Simplification

 
To make a sound more efficient, we can also simplify it. For example, keeping only parts of a sound effect can give it contrast.

In this scene from Kill Bill , the weapons that spins continuously should logically make a continuous sound …

7 The imposture

 
It is perhaps the most widely used trick. We often replace sounds with more detailed or more spectacular effects. But sometimes we associate an image with a totally different sound.

Example: in reality, the silencer of a firearm only slightly reduces the detonation. To differentiate this sound, sound designers have invented a tubular and resonant sound effect, which recalls the cylindrical shape of the silencer. This sound, which has become a cliché, is far from reality. But as we do not hear it every day, it has become the only reference for many people.

The french movie Les tontons flingueurs delights us with very creative silencer sounds.

All these sound tricks are used for a better storytelling. In a film, the sound purpose is to provide emotions. What would movies be without the sounds of laser with silencer in space?