Capturing Your Audience: How to use Subconscious Sound Techniques in Your Film
Updated: May 25
Here at 344 Audio we are big believers in the use of Sound to affect viewers on a physical, mental and emotional level. This use is demonstrated with many practical examples.
The Tibetan Singing Bowl fills a room and our heads with an almost meditative resonance and focus, the Tribal War Drums of yesteryear filled our ancestors minds (and bodies) with fear and blood lust, ASMR responses come from the use of soft voices and delicate sounds which help calm anxieties and induce relaxing sleep.
In this post we offer insights into how you can use the intricacies of the human body and psycho acoustical phenomena to capture your audience with Sound.
The Physical Response
Sound in Film should help tell the story, establish the location and form a larger world around the screen. If you want your film to use sound systems to their full potential, you may want to evoke a physical response from audiences in certain scenes. There are many ways to do this and many reasons why you would want to.
One of the most common comes with the use of low frequencies (120 Hz and under) employed through synthesis, percussion and sound design layers. Certain low frequencies affect internal organs and the body through vibration. This gives moments in film a sense of status, authority and size when used sparingly and is a great way to accent action, horror and dramatic moments in your piece. The soundtrack should be a journey though, and not a constant barrage of low frequencies, as this could lead to the effect losing its power. A great example of where we used this technique was in Feature Film 'Road' by designing a sub bass drop just before two super cars approached, giving them a further sense of power and speed.
Another tool that will affect audiences on a physical level is creating loud moments in your film - this can be used to raise the audiences heart rate through mild discomfort, remember though - the human brain works on comparison, your film's mix should flow in a way that gives the audience quiet moments, making the loud moments feel bigger. One of the most common uses for this is jump scares in horror movies.
A final way to affect the audience physically - is through the use of music. Upbeat pieces can cause an increase in heart rate and breathing, whilst calmer, more relaxing music offers a decrease in heart rate and breathing, so definitely think about which scenes could benefit from this when working with the Composer.
The Mental Response
The brain is very, very powerful when it comes to sound and because it takes electrical signals from the ear and interprets them for hearing, there are many responses that get attributed to certain audible triggers.
A useful way to story tell with Sound and the human brain comes from repetition. You can repeat sounds in pivotal story moments to remind viewers of a location or character, or to reveal a narrative moment. We used this in Feature Film 'Six Rounds' where our boxer protagonist is reminded of earlier moments through the use of the same Waterphone sound, which becomes distorted to show that he has accepted defeat.
Another mental response with sound comes from the exploitation of the Misophonia response. Misophonia is the hatred of certain sounds, one we almost all experience is 'nails on chalkboard' which gives us an anger response. Misophonia varies widely from person to person but thankfully there are sounds that most people hate, which can be used to emphasise horror and psychological pseudo fear in your films. These sounds are mostly related to metallic, stone or plastic items which cause uncomfortable resonances in our ear at 2-5 kHz, so bare that in mind when designing your scary scenes.
The Emotional Response
Emotions are intrinsically linked to sounds in visual media, partly due to our survival instincts and partly due to the influence and conditioning from the world around us.
A commonly adopted storytelling tool comes from applying sound effects that have emotional associations linked with them. Certain sounds are associated with sadness and reflection for example: church bells, dogs whimpering, rain, human crying, a solo violin, a flat-line on a heart rate monitor, minor chords - all of which will likely emphasise moments in your film. Some sounds create fear - dogs barking, whistling cold wind, crows, fire, thunder, roaring animals, avalanche, volcanic eruption or earthquake. Other sounds create a sense of happiness and tranquillity: birds chirping, soft breeze, major chords, water lapping, eastern instruments, wind chimes, water bubbling, laughter, cats purring, applause. With these sound assets you can take many subjective scenes and give them a more concrete emotional canvass. We used this technique in Short Film 'I'm Not The Devil' where reptile hisses and animal roars were layered to accent the toughest enemies the protagonist faced, allowing the audience to empathise with his fear and struggle.
A second technique is the use of ultrasound frequencies (above 20 kHz) and infrasonic frequencies (under 20 Hz) which affect audience emotions in varying ways. Infrasonic frequencies are known to interfere with human perceptions and emotions - it has even been studied as a sonic weapon by the military - many cinema sound systems don't output these frequencies, but it is an interesting tool if your viewers are listening on a sound system that goes under 20 Hz. It has been rumoured that films such as Paranormal Activity employed Ultrasound and Infrasonic frequencies to give feelings of discomfort and fear response to the audience even though they couldn't detect the sounds consciously. Although many cinemas don't output these frequencies, they can still alter our perception of sounds within the hearing range.
A final tool is music, which is one of the strongest ways to get your audience emotionally invested. You can switch between responses fairly quickly. The soft embrace of a choral section through to the damning thump of the contrabass offer a variety of timbres that should be combined with musical intervals, experimenting with this is the best way to find direction for your piece. A combination of interweaving music and sound offers the smoothest and most immersive emotional compass.
Use these techniques where appropriate and you will create a deeper connection with your audience. Your intended message and narrative can connect with them more than just consciously, so capture your audience with sound on your next project.
If you enjoyed this article please check out our ultimate guide to audio post- production: https://www.344audio.com/post/the-ultimate-guide-to-audio-post-production-sound-design