The next revolution in sound is upon us. It's digital, of course, and the first tangible offering for consumers is the Sony CDP-101 player, along with the new compact digital discs known as CDs. Both the discs and the player are totally different from conventional or analog records and players.

The CD, to begin with, is 12 centimeters (about 4.7 inches) in diameter. Playing speed varies from 200 to 500 rpm. Only one side is recorded but it holds an hour of stereo. Sound is stored as a series of digitally encoded microscopic "pits" with an overlay of clear plastic. The pits are scanned by a laser within the machine, which also has the circuits that translate the digital data into an audio signal. This recovered audio is then fed to a normal amplifier or receiver via the high-level or auxiliary inputs and may be heard over loudspeakers and headphones.

Why the fuss over digital? For one thing, it captures at least half again more of the dynamic range of live music than the analog process can (90 decibels compared to 60. This is less a matter of loudness than of preserving the full span of the difference between the loudest and softest passages in a piece of music -- a feature that can be as germane to realistic sound as is the reproduction of the full frequency range. Moreover, the digital process not only raises the decibel ceiling, it also lowers the decibel floor, so that most or all of the noise associated with conventional recording methods is banished. With a quieter format to contain it, the music sounds much clearer even when you play it softly.

Another plus is that copies of digital records can be (or, at least so far, the ones sampled have proven to be) as good as the original master tapes that generated them. Loss of signal and rising distortion no longer are conditions of the very act of duplicating an original source for mass production.

Nor, for that matter, will the CD you buy deteriorate with use. The new disc has no physical contact with the tracing laser. It's impervious to dirt and almost totally resistant to warpage. You can handle it without fear of smudging or damaging it. For all practical purposes, it's a permanent record that should sound as good years from now as on its first playing.

It's also more compact than conventional discs, and it obviates the concern over playback cartridges, stylus replacement, record-cleaning, and so on that have long bugged record owners.

It also implies that the conventional turntable, arm and pickup are marked for eventual obsolescence. This is hard to foresee, but it surely is closer than it was only six months ago. There will probably emerge a gradual replacement trend with many consumers keeping their present (analog) record players to handle existing record collections -- for perhaps another five years or so.

Much depends on prices for the CD and its player, as well as the speed and enthusiasm with which record companies begin issuing the new discs. The Sony device, to be available in the U.S. in March, will sell at first for $1,000. The cost will drop as time goes by.

The CDs now list for $15 to $18 apiece, similar to the price of a conventional "audiophile" disc. These prices also are expected to come down. As for availability, more than a hundred titles, classical and popular, have been announced for midyear by such labels as Deutsche Grammophon, London, Phillips, Mercury and Polydor.

The economic crunch, of course, has kept other labels from making public commitments. Insiders believe, however, that the attractions of digital -- both to the industry and to consumers -- are irresistible. Most record companies have been mastering in digital for some time now, and so it would not be all that difficult for them to make CD copies for general distribution. Many feel, in fact, that a digital tide may be just what's needed to revive record sales.