For example, say 100 people each read / sang an identical passage into a recorder. It seems as though the frequency, amplitude etc that is captured wouldn’t anywhere near specific/precise enough the be accurately represented when played back. I.e what variables are at play that allow us to easily discern the 100 distinct voices when replayed? Thanks!
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If we’re talking about a mechanical device like a tape recorder, then the answer is reproduction fidelity is mainly determined by one factor: Tape to head speed, or how fast the tape moves across the recording/ playback head. Professional machines used in recording studios move the tape at 15 inches per second (ips). Home reel to reel units typically roll at half that, or 7-1/2 ips. At the low end, cassette tapes (remember those?) Turn at 1.875 ips. The reasoning is the faster the tape moves, the more tape you have to record every second of every nuance.
Then we get to the new fangled stuff. Digital recordings. And here we have a similar situation, even though nothing is actually moving. In digital it is called the Sampling Rate. It’s a bit hard to describe without using charts and diagrams and 8×10 glossy photographs with circles and arrows and a paragraph on the back of each one describing what each one is in case you want to use each one against me in a court of law. BUT.. the more often you take a sample of something, the closer you get to having the whole thing.
Human hearing frequency response ranges from sometimes as low as 20 hertz (cycles per second) to almost 20,000 hertz. Digital sampling rates most used are 8,000 hz, 44,100hz and 44,000hz for professional quality equipment. If the human ear can hear 20,000hz and we are taking a sample of the sound at TWICE that rate, I think we’re getting the whole picture.
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