[Arny Krueger]

Arer there really scientists who believe that sound quality involves
non-measurable parameters?

About well-known switchmode power amplifier designer Bruno Putzeys:

http://spectrum.ieee.org/feb08/5924

"
He went through four generations of circuit boards without listening to any
of them. Instead, he connected each board to an audio analyzer and then
rejected it because the results weren't what he wanted. The fifth iteration,
though, looked good. Just before Christmas 2001, he brought a pair of the
amps home and connected them to the speakers in his living room. He put on a
CD of Spanish classical music and selected a song by the 18th-century
composer Juan Francés de Iribarren, "Viendo que Jil, Hizo Raya." He settled
back in a chair and listened. It took him just a few seconds to reach a
conclusion: "Straight in the bull's-eye."
"

The point is that Bruno Putzeys clearly believes that technical measurements
were sufficient to establish the sound quality of a high end power
amplifier.

Also:

http://www.6moons.com/industryfeatures/etf06/etf_2.html

"
The finale was a toss-up because one of the two finalists did not survive
the finish line. The winning design was by Periklis Gurdouparis from Greece.
It had very cheap Chinese D/A-chips and lots of tubes in it. The following
day, Bruno Putzeys of uCD/Philips spoke about making audio measurements
using DACs. He had three of them. One was last evening's winner, the second
a non-oversampling design and the third his own brainchild. The shoot-out
winner measured fairly decently, showing a typical distribution of
distortion components from a tubed output stage. The non-oversampling DAC
was more wanting in this respect but Putzeys didn't condemn such designs
entirely. His own DAC measured essentially perfect - the measurement values
were as good as they can be in practice.
"