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wrote:
wrote:
Harry Lavo wrote:
We were speaking specifically of his latest round of
loudspeaker tests, which Sean himself describes as "monadic".

Either provide a quote and citation, or admit you are making
this up.

I visited Sean Olive at Harman last March. Yes, he does now
do monadic testing, with one speaker presented at a time.
The series of presentations does include a hidden reference
of known quality.

I believe he discussed this in his most recent AES paper, but
I need to look it up when I am in the office to confirm.

The most recent paper in the databse is the 2003 paper on
preference in trained vs untrained listeners, which I have in front
of me. The paper can be downloaded from the AES site, for a fee.
I haven't seen the newest issue of the JAES, and I don't know
how fast things get into the database, but I'll assume you
meant to 2003 paper.

The 2003 article uses the Harman lab to do four way (four speaker)
and 3-way (three-speaker) tests. I quote:
//
The four-way test involved
multiple comparisons among four speaker rated independently using
four different programs. A test comprised four trials in the morning,
repeated in the afternoon for a total of eight trials [for the three-way test
where there was only a morning test].
..
..
..
All tests were double-blind using monophonic (single-speaker) comparisons
Before each test, listeners were given their instructions and were free
to ask questions about the test procedure.

In both tests the program order was randomized. For each trial the
control control computer determined randomly the letter (A-D) assigned
to each loudspeaker. Listeners were provided feedback through an LCD
monitor that indicated the current loudspeaker being played.

Switching between loudspeakers in each trial was performed in a random
seuqence by the experimenter. THe music was paused during the 3-second
interval required to substitute the positions of the speakers. [There
follows a discussion of the possible effect of the silent interval]
..
..
..
The presentation time for each loudspeaker was typically equal to the
length of the program loop (15-30 seconds) and shortened to 10-15 seconds
toward the end of each trial. Switching continued until all listeners
had entered a rating for each loudspeaker, at which point the next trial
would begin. A trial typically lasted 3-5 minutes, with an entire session
typically lasting 15-20 minutes.

For the four way test listeners were told not to discuss their responses with
one another until the end of the second session. All listeners were shown
their results after the completion of hte test.
..
..
..
[from the instructions to listeners]:
In these instructions you will be judging the sound quality of different
loudspeakers and rating them according to your personal preference. You MUST
enter a rating for each loudspeaker in the appropriate box after the program
selection has ended. Please enter your ratings using the following preference
scale

[scale graphic]

Your rating can contain up to one decimal place (e.g. 7.3, 2.5)

DO NOT GIVE TIED SCORES IN ANY ROUND
If you do, the computer will ask yuou to reenter your ratings.

You should separate your preference ratings amond different speakers to
reflect your relative preference between two speakers. Use the following
guidelines:
[guidleines graphic]

Finally , we encourage you to write comments about what you like anbd dislike
about the sound of the speakers you are comaring: what aspects is it about the speaker
that makes you prefer it (or not prefer it) over the other speaker(s)?
//

The four prgrams , btw, were works by James Taylor, Little Feat, Tracy
Chapman, and Jennifer Warnes "selected on the basis of their ability to
revela spectral and preferential differences between differeent
loudspeakers in over 100 different louspeakers in over 100 different
listening tests and varioous listener training exercises."

From this I gather that the test proceeded as follows:
listeners were given instructions, then a 'lazy susan' (behind an
acoustically transparent screen) containing
four loudspeakers rotated to bring the first speaker to the playing position.
The first program is played until all listeners have rated the speaker on
the preference scale. Then a different -- and the listeners know it
is a different one, just not *which* one -- loudspeaker is brought into the
playing slot (this takes 3 seconds) and it plays the same program.
This is done for the remaining speakers. This constitutes one trial.
Then the whole process is repeated, using the second musical selection
from each of the four speakers. Four musical selections means four
trials in total per test. (And repeated for the four-way speaker
comparisons).

I also gather that speaker *difference* is a given for Olive
in these trials, particularly as he uses musical materials intended
to make the contrast as clear as he can.

This does not sound to me like one of Harry's monodic listening
tests -- done at home, with long listening intervals, etc.

--
-S
"The most appealing intuitive argument for atheism is the mindblowing stupidity of religious
fundamentalists." -- Ginger Yellow