Dither was developed because it's technically better. Audibly inferior though? Perhaps, with utterly exceptional source material (e.g. test tones) and when the output gain is high enough for peaks levels to be uncomfortably loud.
In reality, many recording studios have a higher ambient noise level than the dither, making it redundant in practice — the lower bits are already noise, so audible quantisation artefacts weren't going to happen anyway. That said, dithering is pretty much never worse than not dithering, and almost all tools offer it, so everyone does it.
24 bits is important because it gives the recording engineer ample headroom, and it gives the mixing and mastering engineers confidence that every last significant bit caught by the microphone will survive numerous transformation stages intact. Once the final master is decimated to 16 bits per sample, you know that your 16 bits will be as good as they could have been.
Have you actually heard the difference between simple dither, noise-shaped dither, and non-dithered 16-bit audio? A test tone is the worst possible way to hear what they do.
24-bit audio is used because you want as clean a source as possible.
This also applies to mastering for output at the other end. With the exception of CD and MP3, most audio is delivered as 24-bit WAV at either 44.1, 48, 88, or 96k.
Even vinyl is usually cut from a 24-bit master. Here's a nice overview of what mastering engineers deliver in practice:
https://theproaudiofiles.com/audio-mastering-format-and-deli...
Dither is noise. Well chosen noise, very quiet noise, but noise nonetheless. Whether the signal is noisy for one reason or another, the consequences at the point of decimation/quantization are the same. Either way the least significant bits are filled with stochastic values and the desired signal isn't plagued with quantization noise artifacts.
> Have you actually heard the difference between simple dither, noise-shaped dither, and non-dithered 16-bit audio? A test tone is the worst possible way to hear what they do.
...is the sort of thing someone who hasn't done a blinded listening test would say. Stop assuming the commercially successful "experts" are also technical experts, because few are. I doubt more than a tiny fraction could describe what a least significant digit is.
(Cutting vinyl, a hilariously lossy process that requires compression and EQ to avoid the needle jumping the groove, doesn't need a 24 bit master. Barely needs a 14 bit master. But since an extra hundred megabytes of really accurate noise floor doesn't make anything worse, they do it anyway.)
Their words mean very little.
I totally get going for 24 bit over 16 for the noise floor, though.
Such audible differences constitute a testable claim. So far, the number of claims that have withstood reasonable test conditions is zero.
Nobody is arguing that 16 bits is enough during the recording and mixing process. If they are claiming that 16 bits is insufficient for consumer distributed music, they need to go back to remedial science class.
I'm all in favor of keeping sample sizes better.. but raising the price for everyone by 10-20%, so that less than 1% can take advantage of it is a bit ridiculous.
While people here like to quote that infamous looks-like-science-but-isn't Xiph video, the reality is that a lot of professional engineers absolutely can hear the difference.
If you have good studio monitors and you know what to listen for the difference between a 24-bit master and a downsampled and dithered 16-bit CD master is very obvious indeed, and there are peer reviewed papers that explain why.
Dither was developed precisely because naively interpolated or truncated 16-bit audio is audibly inferior to a 24-bit source.
Many people certainly can hear the effect of dither on half-decent hardware, even though it's usually only applied to the LSB of 16-bit data. From a naive understanding of audio a single bit difference should be completely inaudible, because it's really, really quiet.
From a more informed view it isn't hard to hear at all - and there are good technical reasons for that.
For synthesis, you don't want dither. You want as much bit depth as possible so you can choose between dynamic range and low-level detail. So 24-bit data is the industry standard for orchestral samples.