| If the sample clock edges aren't very (very very very) regular, on a sample-and-hold ADC, the waveform isn't sampled evenly and that manifests as noise that swamps the detail provided by the higher bit depth. This is called "sample aperture jitter". Requirements scale linearly with frequency and exponentially with bit depth. These a calculator here: https://www.analog.com/en/design-center/interactive-design-t... https://www.analog.com/en/technical-articles/aperture-jitter... Sure enough, 32 bits sampling a 96kHz signal, which is the Nyquist frequency of 192kHz sampling rate, is 0.3fs. At 24 bits, it's more like 100fs, which is much more doable, but still not easy.
Which is why audio bit depths usually don't go to 32 bits, despite formats like FLAC supporting that. The practical upshot of this and other noise sources is that higher audiophile-grade bit depths and sampling frequencies are quite likely to have at least some of those bits swamped out by noise on real hardware. This is just getting the audio recorded. Playing it back as physical sound waves adds something between quite a bit and radically more noise to the signal, even if there's never any lossy compression. |