Spectral Processing

Abstract

In this chapter, we will explore the fundamentals of the theory of frequency domain processing of audio. The text begins by exploring the most relevant tools for analysis and synthesis: the Fourier transform, the Fourier series and the discrete Fourier transform. Following this, we look at some applications in filter design and implementation. In particular, we show how the fast partitioned convolution algorithm can take advantage of the theory outlined in the earlier sections. The chapter goes on to discuss the phase vocoder, with analysis and synthesis code examples, and its various transformation techniques. Finally, it is completed by an overview of sinusoidal modelling and ATS, and their implementation in Csound.