Several forces are converging to swing the attention of the cable industry toward high quality stereo audio. These include tv multichannel sound, digital audio as an encryption technique, the new pay audio services, and Compact Disc digital audio in the consumer marketplace. Several incompatible systems have been proposed for transmitting high quality stereo audio over cable plants. Since each has been optimized for its own particular purposes, selecting one as a standard involves a complex set of tradeoffs.