The Evolution of Digital Audio Technology

Digital audio technology is allowing music and speech to be easily and readily accessible to most people, since these signals are treated as digital media and, hence, are significant components of the information-age revolution. From its commercial introduction via the audio Compact Disc, CD, approximately 20 years ago, this technology had a meteoric evolution which have seen the introduction of numerous methods, techniques, systems and formats and has allowed the users to benefit from reductions in the size of digital audio equipment and its cost. An overview of these developments is presented here with a critical assessment of their significance, along with a reference to many important publications and events. It is shown that this technology is mainly rooted on three constituent evolutionary components, namely, (a) digital electronics and computer technology, (b) DSP theory and techniques, (c) auditory modelling. Based on the analysis of these components, some conclusions are drawn, which allow the prediction of future trends concerning the evolution of this technology.