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by ChrisLomont 1478 days ago
>we were talking about digital audio & the perception thereof by human listeners

Actually, this thread was on sampling theory and whether or not Nyquist perfectly recreated original signals. The only mention of anything about human perception in the chain you're replying to is me writing that good engineering can push errors outside human hearing, while pointing out that it is not the original signal. All the other posts in the thread you claim is about human perception are not about human perception. They're about signal reconstruction with one mention of how that applies to hearing.

>Do you argue like this in all your interactions with other people?

No, most of my friends don't make incorrect claims then double down on them when better information is pointed out. They also don't tend to claim an entire conversation is about a different topic than it was.

You: "Up to the Nyquist limit, a digital signal will completely recreate the original signal". No, as explained.

You: "Digitisation does not result in square wave output anywhere in the output chain" - again false, even for audio, as explained above. Thinking that output is a nice set of pure sine waves making the original band limited (which is also an approximation) leads people to flawed thinking. Realizing the how and why of what actually comes out is useful.

You imply pushing things below a noise floor makes them indistinguishable from noise - this isn't true in general, and is not even true in audio. There are even audio products that use signaling below the noise floor. Repeated misunderstanding of what a noise floor is (and isn't) is extremely useful, even in audio. The other examples were to make it clear there is useful knowledge here.

Understanding these nuances is useful for even audio to understand that reconstruction is always a design tradeoff on where you want to put the errors - and that you never are reconstructing the original signal.