Many of the world's most seasoned Sound Designers claim that natural sound sources garner more worthwhile results than synthesised ones. Even on exotic design elements such as sci-fi and fantasy weapons and creatures, the process of recording makes elements sit better in the mix, but why is this?
The Origin of Sound Waves
The biggest difference between synthesis and field recordings is the origin of the sound wave. Most subtractive synthesizers generate analogue waveforms like sine, square, triangle and sawtooth, each containing different harmonics which provide a timbre. The sound designer can then use a filter to remove low or high frequencies, further shaping the sound. Next comes modulation, envelope generators and low frequency oscillators which add movement to the sound.
Recorded sounds can be much more varied, due to the millions of possible sources available in the world. Human vocalisations for example, are generated in the vocal folds, through vibration - which then resonates in the throat to create recognisable speech. Because of the elaborate nature of this process, the resulting waveform is far more complex than those generated in subtractive synthesis.
Alongside tonal waveforms, many synthesizers can generate white noise. Natural sounds are also quite often noise based, but they constantly shift in frequency, amplitude, distance and timbre which makes them distinguishable from synthesised sound. All of these factors add modulation, resulting in a constantly shifting sound wave.
It is this modulation that helps make your sound design believable to audiences. Once a sound is being modulated heavily, it more closely resembles human speech and other natural sounds.
Considering the ability of the human brain to process and evaluate these complex waveforms, we can conclude that using a synthesised source will allow your design to be more easily detected by audiences. Complex processing can help alleviate this to an extent, but a field recording captures these modulations at source. Recordings with processing will provide you with usable results faster than traditional synthesis.
However, emerging technologies and advances in computer hardware have allowed programmers to create alternative synthesis methods, such as additive and physical modelling, which use combinations of sine waves and resonators respectfully to replicate natural sounds.
Can You Hear The Difference?
Here we have an exterior wind sound - is it a synthesised sound or a field recording? Let us know what you think below.
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