High Resolution Audio: A History and Perspective

Exploration of audio at digital resolutions higher than CD began in the late 1980s, arising from a wealth of interdependent sources including listening experiences, rapid technical advances, an appreciation of psychoacoustics, acoustic measurement, and an ethos that music recording should capture the full range of audible sound. High resolution formats developed and were incorporated into successive generations of distribution media from DVD, SACD, and Blu-ray to internet downloads and now to streaming. A continuing debate throughout has been whether, and especially why, higher resolutions should be audibly superior. This review covers the history of the period, focusing on the main directions that drove experimentation and development up to the present, and then seeks to explain the current view that, beyond dynamic range, the most likely technical sources differentiating the sound of digital formats are the filtering chains that are ubiquitous in traditional digital sampling and reconstruction of analog music sources.