As a test, I downloaded files from
HDtracks.com, an online retailer specializing in hi-res audio, plugged a device known as a digital-to-analog converter (DAC) into my computer and listened over earphones. My optimism did not lead me astray. To a few of my colleagues and me, the higher resolution made the sound more resonant, realistic and full. Unlike high-definition video, which can result in disconcerting detail (hello, pores), hi-res audio smooths more than it sharpens. The improvement is significant, yet subtle—easily masked by the rumble of mass transit or even the whoosh of a nearby dishwasher. The quality upgrade will be lost if you're not in a quiet space.