The Science of Sound Design and Production In Filmmaking

28 May 2020

4 Min Read

Any film in any form and made for any purpose contains two main elements, the image, and the sound, these are the only elements that help the audience understand the film’s story. It’s only through these two mediums that by watching a pizza commercial we would feel its deliciousness. Or when watching a scene in which the wind is blowing in a field -although we can’t feel the wind on our skin- we can imagine ourselves in that field because we can hear its sound and see it’s moving the leaves. So whatever feelings we want to induce through the course of the film, should be delivered through sound and scene.
In today’s blog, we want to study how sounds are strong stimuli for creating feelings and how sound designers use some techniques to induce feelings and make us understand the movie way better.

Sound Localization

Localizing sounds is what our brain does all the time in real life. When someone calls you from the other room, you know where the sound is coming from because of the complex auditory system gifted to your brain. So for experts in filmmaking who want to give you wonderful experiences through their films, it’s crucial to make the sounds as realistic as possible. That’s why in movies most of the sounds have direction and when watching it with a high-quality sound system, you can literally feel the direction of the sounds. This has helped war movies a lot in creating tension by moving planes above your head and throwing grenade sounds at you. One of the latest movies in which the sound design is created around localizing sounds is the oscar-winning movie 1917 by Sam Mendes which walks you through the operation of a fatal mission during WWI.


Another function of our auditory system that helps sound designers to induce feelings to our brain is using infrasound. While a human is able to hear sounds from 20 HZ to 20,000 HZ, infrasound is just under 20 HZ. That’s why sound designers use infrasound -which is usually disturbing for us- in horror films, to make us even more anxious and scared of what we’re watching. The point is that infrasound is a hidden sound that we can not hear but we can feel so it affects our feelings, therefore it’s a good trick.

Infrasound Graph Used In Horror Movies

Auditory Illusion

This one is not about our brain function but is a scientific trick in composing that drags your brain into an illusion. One of the most effective techniques that create an illusion is called the Shepard tone. In this technique, the composer stacks three different tones on top of each other, separated by an octave in a way that the top one reduces in volume as it continues, the middle one remains loud from the beginning to the end and the bottom one gets louder and louder. The result of using such sounds in the loop is the illusion of a sound rising constantly and it adds mystery or tension to the film. One of the masters of using Shepard tone is the genius composer Hans Zimmer that used it in movies like Interstellar, and Dunkirk by mixing it with the ticking sound that stresses the shortage of time and as said before, creates tension.

Hans Zimmer and Music Composition
Music Composition Process

Mixing sounds

An attractive technique that has been used in many movies is mixing sounds for different purposes. Think of observing a picture of a jungle and hearing or let’s say remembering the sound of birds in a jungle that you once been in. This happens mostly when characters remember some conversations from the past in a related situation. Like a boy who remembers his father’s advice of being strong while he’s doing a boxing fight. But some sound designers do it even more creatively. Take the scene in which Theodore and Catherine are getting divorced in the movie Her. The sound design gives you everything you should know and feel. In this scene, their tone when talking to each other with warm voices and the way they look at one another reveals that they’re still in love. The beauty of sound mixing happens when Catherine is signing the divorce papers, while Theodore is staring at her. She signs the first paper and Theodore suddenly remembers all the romantic moments he had with her while we can still hear the sound of the place they’re in and the sound of papers getting signed by Catherine. Although he is there physically, his mind is experiencing all those moments with her again but the memories have no sound, meaning that they’re hidden in Theodore’s mind and he’s not revealing it to her. This mixing technique is what represents the overlap of the moments in our mind and let us think of two things simultaneously just by the art of placing the right sounds in the right place.

Joaquin Phoenix & Rooney Mara Scene in the movie Her

The Association of The Instrument

This one is more psychological and it is a classic one in which some sounds or let’s say instruments are associated with some feelings that create a theme which is very helpful for sound designers as experts in creating themes with sounds. A brilliant example of this is again the music composition of Zimmer for Interstellar in which he used the organ instrument which is generally heard in churches. The reason Zimmer and Nolan decided to do this is that the story of Interstellar somehow connects us to a world that is still unknown therefore the sound of the organ which represents the metaphysical world of god and heaven, feeds the story with the feeling of experiencing a world above our physical one.

The Organ Music Instrument

Nolan in this film tries to make you think above the capabilities of the human being and reach out to the world that might come some centuries later. So choosing instruments with some common associations to create or complement the theme and ambiance of the story is the choice of the professionals in this field. This is also related to the psychology of music in which each instrument creates a special mood and therefore waves which is able to lead the brain waves. And this is why many sound designers are somehow scientists of the sound realm to hack our minds by using sounds.


All in all, a job like designing sounds for films, requires an understanding of how sounds work in the world and what is their impact as one of the fundamentals of life. In this approach, a sound designer knows the psychological, physiological and philosophical role of sounds in our thought process and uses it expertly to move a story and a film to the ideal area of catharsis.