We begin this journey with a blueprint. Computers are a wonderful vehicle that can take us to amazing places, but without theoretical underpinnings they are a car without a roadmap. They cannot show us a destination or a route, only a means of travelling. As sound designers we work within an enormous context, an incredibly rich landscape, encompassing physics, maths, psychology, and cul- ture. The history of sound design goes back to before the Greeks and Romans1 and brings with it such a body of terminology and theory that it’s easy to get lost. Since we are concentrating on the general case of sound I will not dwell on musical instruments, song and musical scales, nor most of the five decades of analog electronic theory that precede digital representations. The following posts are a rapid tour of what could easily fill three textbooks, if not an entire shelf. To provide a modern view that ties together these foundations I would like you to keep in mind while reading. It shows sound design as a structure supported by three pillars, three bodies of knowledge, which are:
First we look at sound as a physical phenomenon, as vibrations within mate- rials that involve an exchange of energy. These are the subjects of mechanics, material dynamics, oscillators and acoustics, covered in other posts. Some equations will appear, but on the whole a qualitative approach is taken.
Mathematics plays an essential part for understanding how digital computers can make a facsimile of real-world dynamics. Chapter 7 will give an overview of digital audio signals. Although we venture into computer science in order to see how to represent and transform such signals we will keep it light and avoid difficult analysis.
And since sound is a sense, a human experience, psychoacoustics will be needed to help us understand how we perceive physical sounds, how we extract features and meaning from them, and how we categorise and memorise them. Our personal experiences are subjective and it is hard to objectively map internal encodings. However, the ideas presented here are known to hold true for most people and have solid experimental evidence from cognitive psychology.
Technique and Design
Bringing together these three supporting subjects, the physical, mathematical, and perceptual, we arrive at the final chapters in this part, which deal with technique. Here we will examine approaches to deconstructing sounds according to their physical basis and our experience of them. This reveals physical processes that tally with perceptual processes. Finally, we’ll see how to turn these analytical models into new sounds with the desired behaviour, and see how to control them using signal-processing techniques.