Audio effects are used pervasively in music performance and production, and the creation of new digital audio tools is a significant industry. They are also commonly used in game production, broadcasting, and film and television. This book is intended as an educational textbook on audio effects, with relevance to audio signal processing, music informatics, sound engineering, and related topics. It provides fundamental background information on digital signal processing, focusing on audio-specific aspects. This constitutes the building block on which audio effects are developed. It integrates theory and practice, relating technical implementation to musical implications. This book can be used to gain an understanding of the operation of existing audio effects or to create new ones. It includes detailed coverage of common audio effects (and plenty of unusual ones). It includes discussion of current digital audio standards, likeVST. Accompanying source code is provided in C/C++, for audio plugin development using JUCE. Each section of the book also has examples, exercises, sound samples, lecture slides, and additional information on related topics. This second edition includes revised and expanded chapters, with new content on equalization, distortion, phase vocoders, and reverberation. It also has new chapters on immersive audio and on advanced concepts in audio programming, revised source code using the latest version of JUCE, and corrections and improvements throughout.