how is digital sound created?

+1 yage! It is obvious that millercarbon did not know what "interpolation" is!

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

@yage was talking about 'error correction' and indeed that is done without guessing. 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. Muting is the final stage where the data's too far gone even for interpolation/concealment.

@abraxalito

Thanks for that clarification - good to know. It's a linear interpolation, so very different from the interpolating filters used in the DACs themselves. The reference I found is at this link - https://www.pearl-hifi.com/06_Lit_Archive/02_PEARL_Arch/Vol_16/Sec_53/Philips_Tech_Review/PTechRevie...

Of course, all this only applies to compact disc digital audio. In case anyone is interested, I found an overview of the error correction approaches in other disc formats - https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.462.3524&rep=rep1&type=pdf

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.

This is like, imagine the OP asked how does the analog signal turn into sound? The answer is, the analog signal goes through a voice coil, creating a magnetic field that pushes the coil in and out, which makes a cone go in and out, which moves air, and that makes sound.   

But instead of that we get lots of stuff about ports and crossovers and amplifiers. All very good to know. If only it had anything to do with the question.....