Michael Lavorgna writes:
This is really great news for anyone following the hi-res audio debate. The debate is simple; some people claim there is an audible difference between high resolution files and lower resolutions, and some people claim there isn't. There have been a bunch of technical articles on the subject but up until now(ish), there's never been proof that everyone agrees upon. No solid scientific statistically significant proof as to whether or not anyone can discern hi-res audio from lower resolutions in an ABX test. The good news is we have significantly significant test results that prove without question there is an audible difference between hi-res and lower resolutions. The not so good news is this happened over a year ago.
I'm going to let you read the specifics of the test yourself over on the What's Best Forum: "Conclusive 'Proof' that higher resolution audio sounds different". Here's the gist of it. One of the co-creators of the ABX Comparator, Arny Kruger a staunch supporter of ABX testing, created a number of files from a 24-bit/96kHz recording he made of keys jingling (I know, but he's the ABX audio expert). Arny sampled down the original recoding to 44.1kHz and 32kHz, then resampled them back to the 24/96 original. Arny's contention was no one would be able to pick out the down sampled files from the original 24/96 file.
He was wrong.