: Digital Audio Fundamentals


What is Digital Audio, Sampling (Digital Audio), Sample Rates and Bit Depths?

In: Other

Not sure what the other things are but sampling is basically: real life sound is a continuous wave, but you cannot save a continuous wave to a computer memory, because the memory works like coloring in squares instead of drawing a smooth curve. The smaller the squares you can color are, the higher the sampling rate would be, so you get a better approximation. (Note: the computer memory stays the same, but what higher sampling rate does is it makes a note of where the wave is at shorter and shorter spaces between points.)

Sound is a wave, think of that sine wave you see on the monitors in movies. We convert that to digital by taking vertical slices at intervals on the time scale, checking the value at each point. Sample rate is how many slices we take per second. The CD sample rate is 44,100 per second, although other formats go up to 96,000 per second. This is thought to be enough that your ears can’t discern sampled audio from the original.

Now that we have a slice, how fine detail does it have? Do we use 0-100 to represent every value under that curve, no matter how high it is? No, that wouldn’t store enough information, meaning the dynamic range of the sound would be too low, so it would sound very bad. A CD uses 16 bits, or 16,556 different values to give us a good dynamic range. Higher quality audio these days uses 24 bits, or over 16 million, to give better dynamic range.