Introduction: Phase Processing, History
Pejman Mowlaee · 2016
This chapter provides the historical background on phase-aware signal processing. We will review the controversial viewpoints on this topic, in particular addressing two fundamental questions: Is the spectral phase important? To what extent does the phase spectrum affect human auditory perception? To answer the first question, the chapter reviews the literature on the significance of phase information in signal processing in general and speech or audio signal processing in particular. We provide examples of the importance of phase in diverse applications in speech communication. The wide diversity in the range of applications highlights the significance of phase information and the momentum developed in recent years to incorporate phase information in speech signal processing. To answer the second question, we will present several key experiments made by researchers in the literature, in order to examine the importance of the phase spectrum in signal processing. Throughout these experiments, we will examine the key statements made by the researchers in favor or disfavor of phase importance. Finally, the overall structure of the book will be explained.