Unfortunately, I am old enough to remember the launch of CD. An astonishing 10 bits (roughly) are used for every 1 bit of the signal. The claim is that errors can be detected and corrected for up to 4,000 consecutive bit errors, and there is no obvious discontinuity if 7,000 bits are wrong. As a demonstration, a 1/8 inch hole was drilled right through a CD and it played with no apparent adverse effects.
Philips knew the benefits of four-times oversampling from the get go which is why its early CD players sounded better than the competition. Oversampling allows much gentler filters to be used.
Philips also recognised the difficulty of trimming resistors in their resistance ladder DACs, and only bothered to decode the most significant 14 bits.
PCM advocates should understand that none of this matters with Direct Stream Digital, where the low pass filter is in the mega-Hertz region and every bit is equally important.
