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Comment by wickedchicken | Hacker News Reader

> two band limited pulse signals with different onset times, no matter how arbitrarily close, will result in different sampled signals.

This is true, but different than what I am arguing. You're saying that a listener over time will be able to tell that the two signals differ. I am saying that a listener will be able to determine this at fractional wavelengths.

It's similar to dithering a high dynamic range signal onto a lower bit depth: more than two samples are required for "evidence" of two different signals, while sampling at a high enough rate will tell you this almost instantly.

Again, I don't know if human ears are able to detect this, just that I haven't seen it addressed in these discussions.

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I'm not sure what you're getting at.

As a thought experiment, let's consider a pulse that has been band-limited to 20kHz. Are you arguing that the analog output of a (filtered, idealized) DAC would look different depending on whether the dac was running at 44.1kHz vs 192kHz? If so, I don't think many people would agree with you.

Any difference in the "timing" of the output wave would have to come from energy that falls above nyquist of the slower sample rate. So, while I agree with you that the timing would be sharper, this is exactly caused by "higher frequencies", not by some other sort of timing improvement.

> Are you arguing that the analog output of a (filtered, idealized) DAC would look different depending on whether the dac was running at 44.1kHz vs 192kHz?

No. I'm arguing this: take a 44.1kHz signal and upsample it to 192. It's the same signal, same bandwidth and everything. Duplicate the stream and add a 1 sample delay to one of the channels. When you hit play, that delay would be there. If you downsampled the 44.1kHz signals after applying the delay to one of the channels, you would almost hear the same thing. The difference is that you could not detect the difference between the signals until after a few samples. With the 192kHz stream it would be unambiguous after 2.

Remember, Nyquist-Shannon holds if you have an infinite number of samples. If your ears could look into the future then what you say is perfectly correct, but they need time to collect enough samples to identify any timing discrepancies.

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