Cognitive Speech Coding

Speech coding is a field where compression paradigms have not changed in the last 30 years. The speech signals are most commonly encoded with compression methods that have roots in Linear Predictive theory dating back to the early 1940s. This paper tries to bridge this influential theory with recent cognitive studies applicable in speech communication engineering. This tutorial article reviews the mechanisms of speech perception that lead to perceptual speech coding. Then it focuses on human speech communication and machine learning, and application of cognitive speech processing in speech compression that presents a paradigm shift from perceptual (auditory) speech processing towards cognitive (auditory plus cortical) speech processing. The objective of this tutorial is to provide an overview of the impact of cognitive speech processing on speech compression and discuss challenges faced in this interdisciplinary speech processing field. In this context, it covers the traditional speech coding techniques as well as emerging approaches facilitated by deep learning computational methods. The tutorial points out key references on fundamental teachings of psycholinguistics and speech neuroscience and provides a valuable background to beginners and practitioners on the promising directions of incorporating principles of cognitive speech processing in speech compression.