I'm not sure this is fruitful going down this road. I try to interject when possible whenever the masses are being misled about DACs. You can tell differences, whether one wants to believe that or not. You challenged me for a citation. This is a typical tactic with the same crowd trying to justify their cheap* soundcards and DACs by trying to tell everyone there's no appreciable difference. I'm not saying that you were doing that, but it wouldn't be surprising if a double-blind test was mentioned at some point, too.
In any event, the citation is meant to illustrate that human hearing (educated hearing) can indeed detect noise floors up to a range of 118 dB. You challenged the idea of whether someone could tell the difference between noise at -87db vs. noise at -90db. I submit that they can under the right conditions and circumstances. That citation at least proves that human hearing can detect noise beyond that. If you want to focus on the mention of a "recorder," SN ratio vs Dynamic Range, etc., then I can't help there.
* There's nothing wrong with "cheap." I build, sell, and have helped design cheap DACs - some of the most inexpensive on the market. The difference is that I don't go around trying to tell everyone that there are no differences among them and that someone should settle for one of them, or a soundcard, or someone's inexpensive but seemingly good-test-results amplifier - instead of continuing a journey through the audiophile experience.
Edited by tomb - 2/19/12 at 1:39pm