how is digital sound created?

abraxalito

If you're claiming that interpolation is all part of R-S coding that wouldn't be correct. Interpolation is specific to audio and R-S codes get used in plenty of application ...

I don't know how it could possibly have been more clear that we are talking about digital audio here.

abraxalito

There is a stage beyond error correction where the data’s too corrupted to do error correction and that’s normally termed ’error concealment’. Its at that point where interpolation - which indeed is a kind of guessing in this context - is used.

It’s all part of error correction, all part of the Reed-Solomon code, and I actually quoted the exact math that applies.

Then there are those who insist that there is no interpolation, or those who insist digital audio results in stairstep signals. That’s why I usually post links to the facts - there is just so much misinformation about digital because it’s not intuitive.

But as I noted, interpolation in digital audio is actually quite rare. That’s how well the error correction schemes work.

yage

There’s no interpolation happening when performing error correction since there’s no ’guessing’

You are mistaken. Interpolation is "guessing" by definition (in this context) and interpolation is part of the CD standard.

The proper bits are either recovered or the data stream is so corrupted that some errors remain. In the latter case, the player may mute the output or cease playback.

That’s how a data disc works because it has to be bit perfect. But it’s not how digital audio works at all. The Reed-Solomon error correction code is part of the CD standard and, as MC noted, it’s all part of the fun math that makes digital audio:
" ... whereas subsequent constructions interpret the message as the values of the polynomial at the first k points a 1 , … , a k {displaystyle a_{1},dots ,a_{k}} and obtain the polynomial p by interpolating these values with a polynomial of degree less than k ..."

millercarbon

... Really good expensive DACs have a lot more quality parts and do a lot more processing trying to smooth the signal out by interpolating values in between the stair steps ...

That is completely mistaken but a common misnomer. The only interpolation that is part of the digital audio standard is when it is used for error correction. Because the data on a CD is encoded redundantly and interleaved (and cached in streaming) error correction is actually quite rare.

Within the bandwidth of the system, the Fourier theorem shows us that digital audio can perfectly describe the analog waveform. If you have doubts, watch this. (Kindly note that I'm not claiming digital audio is "Perfect Sound Forever." But if we want the best sound from digital, it's helpful to understand how it works.)

It's odd how many audiophiles refuse to accept this math, which is conceptually simple even if the details are not. Consider that the Fourier mechanism also explains perfectly how the squiggles on an LP can represent a full orchestra.