24-bit vs 16-bit at a common sample rate - difference?

[jcx]

I put "24 bit" in quotes because no existing audio ADC has noise level that low, "flagship" monolithic audio ADC currently manage ~120 dB A weighted, or 20 bit dynamic range

 

[tranhieu]

and you would be all dead before reaching that dynamic range...

 

[danroche]

I think people are in love with the idea that using 24-bits will yield better sound because it seems to address that age-old misconception that anything digital is made of of blocky, steppy waveforms, while anything analog (even cassette tapes) appears as this lovely, endlessly detailed, fluid wave shape. 
 
There was an amazingly ill-informed story on this back on MTV sometime in the early 1990s, basically a shock discovery piece that warned us that CD waveforms were these horribly unsightly, blocky things (picture a 3-bit digital signal) which somehow "lost" information between the steps that, of course, was magically reproduced on vinyl records and cassette tapes.  I'm assuming they had a "part 2" set to talk about the Nyquist theorem, but this being the grunge era I'm sure I just decided they were all sell-outs and turned off the TV.
 
The unlikely voice of reason on this piece was Megadeth's Dave Mustaine, who explained, in fewer words, that digital was more revealing than analog, and people who preferred the latter were probably just not ready to hear all the warts and imperfections digital was able to offer them.  MTV did not give Dave the last word here.
 
There's an article which restates this old myth on, of all places, howstuffworks.com but I don't feel like looking it up as it will just make me angry.

 

[Justin Uthadude]

Would 2^24 not be an advantage over 2^16 when multiplying by odd ratios to get equalized volume (via replaygain)?

 

 

[jcx]

once the bits are in your computer sound system sw then using 24 bit (or even 32 since that is the "word" size in most PC) represention is reasonable for any processing like digital volume or sw EQ, cross feed and sending 24 bits to a HD soundcard or chip with a "24 bit" DAC would save spending cycles on re-dithering since analog noise in even the best audio DAC will "dither" the output