AES conference London: High Resolution perception, paper about listening test Options

[Kees de Visser]

Unfortunately I wasn't able to visit the june 2007 AES Conference in London about High Resolution Audio.
The paper/presentation about a high-res audio listening test seems interesting. I'm wondering if anyone on HA happens to have been there and can share some information.

preview of the paper session:

Monday, June 25 11:00 – 12:30
Paper Session 2 — Perception

2-1 Which of the Two Digital Audio Systems Meets Best with the Analog System?— Wieslaw Woszczyk,1 Jan Engel,2 John Usher,1 Ronald Aarts,3 Derk Reefman3
1McGill University, Montreal, Quebec, Canada
2Centre for Quantitative Methods CQM BV
3Philips Research, Eindhoven, The Netherlands

In this listening test, two digital audio systems (B and C), and one analog system (A) were tested by 10 test persons who listened to a surround sound scene “live” (without recording). The main question to be answered was: “Which of the two digital systems meets best with the analog system?” Both digital versions had 24-bit dynamic resolution but differed in sampling rate with which the analog signal was sampled. One version © was sampled with a CD rate of 44.1 kHz, the other (B) 8 times faster. There were also two test conditions, where in one condition there was a bandwidth cut off at 20 kHz instead of the 100 kHz that was possible with special 100 kHz microphones and added super-tweeters. For each subject, the experiment was replicated six times, in each of the two conditions. The outcome of each experiment was a 0 or 1, where the 1 means that the, technically best, digital system B has been chosen as meeting the analog quality. The paper describes the test and the outcome.

Without having read the paper, it's not clear to me whether the test was double-blind or not. Apparently it was not possible to replay sources, since the audio source was "live". How reliable would a test like this be ?

[krabapple]

So , how to reconcile these with Meyer and Moran's trials, which used several SACD players, and more subjects, with the conclusion that CD and SACD sound the same at normal volumes? Does it come down to matching digital formats against analog, versus against each other? Surround instead of two channel? THe use of a highly contrived 'musical scene' (an electric motor driving a bicylce wheel in an anaechoic chamber??!!) as probe signal, versus recorded music? THat some listeners may have been in fact judging ANALOG (the live feed) versus DIGITAL (both A/D conversions), in a nonblind comparison?

This post has been edited by krabapple: Dec 11 2007, 08:33