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how is digital sound created?

So sound is a vibration which is created from things rubbing or banging together etc. If stuff isn't interacting with something to create a sound how are sounds created from nothing? I.e in the digital world? Music on an iPod or a beep from a computer? I have always wondered what the noise's are and that come from computers when they are 'thinking' or working - wtf's going on there?

lucaspeni
yage
401 posts
 
If the OP means electronic music or sounds, then I suggest looking up the history of digital synthesizers and FM synthesis.

At its most basic, sound (and music) can be modeled as the sum of sine waves of different amplitudes and frequencies. This is the most important concept to understand and underpins all of digital audio. Here are some links that you’ll hopefully find useful:

https://www.compadre.org/osp/EJSS/4487/272.htm

https://gizmodo.com/digital-music-couldnt-exist-without-the-fourier-transfo-1699155287
millercarbon's avatar
millercarbon
12,531 posts
 
Funny how some analog zealots have not so much trouble listening to digital files run back thru lossy homogenizer tape decks… to wit Famous Blue Raincoat.


https://youtu.be/0AHBw7wItpI?t=24
pedroeb
493 posts
 
Is there something fundamentally wrong with Famous Blue Raincoat? The writer has clearly been agitated by a homogenizer.
swann
21 posts
 
In bits and drabs.
cleeds
6,582 posts
 
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.
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