For the last few months, I’ve been doing loads of research into procedural audio and investigating if it’s yet accessible enough for the average sound designer to get started with. I have determined that it definitely is, and if you’re at least tech-savvy enough to operate a synthesiser, you can get to grips with procedural audio in no time.

During this year’s round of Game Audio North talks, I give a brief overview of procedural audio and had a look at where it’s being used. I ran through the two primary approaches (top-down & bottom-up) and showed how you might tackle a project with a top-down mindset. To demonstrate this, I created a PureData patch that simulated a recording that I took of my convection fan. Without delving into the operational mechanics of the fan, I tried to approximate the features of the sound with simple signal generators and some filters.

Looking at a spectrogram of the recording, I determined that I could simply use some band-passed noise, and a harmonic signal generator.

Sinesum sets the amplitude of the harmonics, which was set to roughly to mimic the spectrogram. Phasor then reads through the table 500 times per second, creating the 500Hz fundamental. The noise is band-passed around 500 to give it more energy around that region, and further low-passed to create that pink noise distribution.

Finally, to make it interactive, a recording of the click is stored in a table and played back every time the switch is toggled. A lowpass filter is used as a logarithmic sweep, which mimics the non-linear build up and decay of the harmonics.

The patches and recordings are freely available to download below, as well as the slides for the presentation, which have loads of great resources for getting started with procedural audio.

PureData-Fan.zip

Procedural Audio GAN’18 Powerpoint Slides