Audio Processes

12 Frequency Domain Methods

12.1	Time Domain and Frequency Domain Processes
12.1.1	Introduction
12.1.2	Fourier Transform Basics
12.2	General Techniques
12.2.1	Filtering
12.2.2	Vocoding and Application of Spectral Envelopes
12.2.3	Delay
12.3	More Sophisticated Techniques
12.3.1	Time-Stretching
12.3.2	Changing Pitch
12.3.3	Modifying Amplitude and Frequency Relationships
12.3.4	Blending and Morphing
12.4	Developing Processes and Learning More

12.1 Time Domain and Frequency Domain Processes

12.1.1 Introduction

The majority of audio processes are constructed to modify and synthesize audio data in terms of time domain signals (amplitude varying over time). This form of audio data is analogous to the variations in air pressure that are received by the human auditory system. ...