ABSTRACT
This chapter explains the basics of digital audio hardware and software. Sample rate conversion is used to apply Vari-Speed type pitch shifting to digital audio. The most common sampling rate for digital audio is 44.1 KHz, which supports frequencies as high as 20 KHz. very soft artifacts related to digital audio is jitter, which is a timing error between sample periods. Each bit in digital audio represents a different amount of the analog voltage, but all the bits carry the same direct current voltage when on. Electricity may travel at the speed of light, but it still takes a finite amount of time to get digital audio into and out of a computer. Some people claim that analog recording is “wider” or clearer or more full-sounding than digital audio. However, it’s simple to prove by measuring, null tests, and blind listening that modern digital audio is much closer to the original source than either analog tape or vinyl records.
