When sound effects are done well, they combine seamlessly with dialogue, music, and moving images to immerse the audience in a story. Ideally, it should never cross the audience’s mind that these sounds were created and added separately; but if you do stop and think about it, the process of making sound effects is utterly fascinating. This article will explore some of the methods used to create different types of sound effects – but first, a little history to set the scene:
Sound effects first appeared in the context of live theater, where people offstage would use physical props to simulate real-world sounds, such as shaking a thin sheet of metal to create a rumble of thunder for Shakespeare’s The Tempest. When radio and recording technology became widespread, radio plays borrowed from the theater tradition, using techniques like banging coconut halves together in front of a microphone to create hoofbeats.
When technology finally allowed motion pictures to feature sound in the early 20th century, the art of sound effects began evolving more rapidly than ever. With the ability to create custom sounds in post-production and sync them to moving pictures, sound editors developed increasingly sophisticated methods of creating lifelike sound effects for films. Beginning in the late 1950s, the BBC Radiophonic Workshop was instrumental in advancing sound design with their experiments in synthesized sound and tape manipulation to create never-before-heard sounds that were perfect for science fiction programs of the day like Doctor Who.
Today, sound effects creators combine all of these techniques with a toolbox of ever-evolving technology to embellish movies, television, games, and technology with ultra-immersive sound. Sometimes sounds are recorded for use in a specific film project – like historical aircraft recordings for a period war movie. Other times, sound artists are simply inspired to create or capture sounds that may be useful for themselves or other creators – like retro anime sound effects or detailed camera recordings.
If you’ve ever found yourself wondering things like, “How are cartoon sound effects made?” (or if you’re interested in creating your own sound effects), follow along as we dive into the fascinating world of sound effects creation.
Most sound effects fall into two broad categories: "real-world" sounds and “designed” sounds. Real-world sound effects include true-to-life recordings of objects, people, animals, and environments with no significant editing or processing. Designed sounds, on the other hand, incorporate creative techniques like layering, processing, and synthesis to enhance “real” sounds for dramatic effect or create entirely new sounds. Here’s an overview of what’s included in each category:
Real-World Sounds
Designed Sounds
Real-world sounds are either recorded in a studio or “in the field” (meaning anywhere outside of a studio). There are infinite recording setups and techniques to use, each suited to different situations. For example, a serious field recordist might carry a multichannel recorder and a surround-sound mic array for recording natural soundscapes, while a Foley studio would probably prefer a single high-quality shotgun microphone with a premium preamp and A/D converter for maximum detail and sound quality.
Whether creating laser gun sounds for sci-fi games or eerie, unnatural ambiences for horror movies, sound designers excel at coming up with unorthodox ways to make sound effects. Between analog and software synthesizers, plugins for creative processing, and techniques like pitch manipulation and time-stretching, the sound design possibilities are truly limitless.
Once sound effects are recorded or otherwise created, getting them ready for use involves a few final steps. First, noise reduction software may be used to eliminate unwanted hiss or hum. Sometimes unnecessary low or high frequencies are filtered out. EQ may also be used to "sweeten” the sound by bringing out the tonal character, and compressors and limiters may be used to help smooth out volume dynamics and prevent distortion from clipping.
Pro Sound Effects takes a more naturalistic approach to editing recordings – opting to process the sounds as little as possible so that sound artists using the files can choose to do that on their own. Instead, the primary goal is to preserve as much of the original recordings as possible, cleaning only when necessary.
After cleanup and sweetening, each individual sound (or set of sounds) must be rendered as its own file. At this stage, files are trimmed to start right at the beginning of the sound and end just as it dies out, with no empty space. Levels are also tweaked at this stage to make sure each sound is loud enough to be heard clearly, but still retain the full dynamic range of the sound.
The final step is to embed metadata in the files such as category and descriptive keywords, or info like number of channels, the recordist’s name, the date of recording, and so on. Pro Sound Effects uses the Universal Category System (UCS) metadata standard for all sound effects files. Having this data attached to the file itself helps ensure that each sound is easily searchable using library management software like SoundQ and that it contains any information a user might need to know, such as languages being spoken in the background of an urban field recording.
There you have it: an introduction to how movie sound effects are made, as well as a few strategies you can try when recording or designing your own sounds. To learn more, check out our blog for interviews with award-winning sound artists like Richard King, helpful sound design tutorials, fascinating mini-docs on film sound pioneers, and more.