Speech and Audio Signal Processing: Processing and Perception of Speech and Music, Second Edition

PART I

HISTORICAL BACKGROUND

The future is a lot like the present, only it's longer.

–Dan Quisenberry

AN UNDERSTANDING of the goals and methods of the past can help us to envision the advances of the future. Ideas are often rediscovered or reinvented many times. Often the new form has much greater impact, though sometimes for fairly mundane reasons, such as greater accessibility to larger computational capabilities. It would be obvious to most that a study of the social sciences would be incomplete without inclusion of the methods and beliefs of the past. In our view, a study of current methods in speech and audio engineering without any historical context would be similarly inadequate.

For these reasons, we introduce the basic concepts of speech analysis, synthesis, and recognition in Part I, using a historical frame of reference. Later parts will provide greater technical detail in each of these areas. We begin in Chapter 2 with a brief history of synthetic audio, starting with 18th Century mechanical devices and proceeding through speech and music machines from the first half of the 20th Century. The discussion continues in Chapter 3 with a discussion of systems for analysis and synthesis, including a brief introduction to the concept of source–filter separation. Speech recognition ...