Why is it called “digital sound” when sound waves are analog signals?
As you say, natural sound is analogue. The digital bit happens only because we send the analogue signal into an ADC (analogue to digital converter), and the output takes the form of a string of digits, which are more capable of being transmitted through wire or radio without change, and free of some common impairments. “The expression “digital sound” is something that the media seem to have adopted without regard to the true meaning of the words. It is true that the original sound is analogue, (and microphones, and loudspeakers are strictly analogue devices) but the recorded (DAT or CD) or transmitted (DAB) sound has been sent in a digital format. Of course, when you listen to the record or the digital radio, the digital signal is converted back to analogue so that it can drive your analogue loudspeaker or headphoneas! In fact there is really no such thing as digital sound, only digital means of recording and transmission!
