In this space last January
, I enthused about the sound of linear 20-bit digital recordings which, I felt, preserve the quality of a live microphone feed. "I have heard the future of audio—and it's digital!" I proclaimed, which led at least a couple of readers to assume I had gone deaf. Putting to one side the question of my hearing acuity, 20-bit technology has been rapidly adopted in the professional world as the standard for mastering. The remaining debate concerns how to best preserve what those 20 bits offer once they've been squeezed down to the 16 that CD can store. Sony's Super Bit Mapping algorithm and Harmonia Mundi Acustica's redithering device have been joined by new black boxes from Apogee Electronics, Lexicon, and Meridian; it appears likely that, in next to no time at all, all CD releases will be offering close to 20-bit resolution—at least in the upper midrange, where the ear is most sensitive.