View Single Post
  #10   Report Post  
Mkuller
 
Posts: n/a
Default Comments about Blind Testing

Bruce Abrams wrote:
Mike,

You have repeatedly brought up the notion that DBTs, particularly of the ABX
variety, only have validity in 'trained' listeners and are useless to the
untrained.


My point is that to be able to identify audible differences in a blind test,
the listeners need to be experienced enough to be able to 1.)recognize them and
2.)categorize them for memory. When I was first starting out in High End
audio, I recall comparing two preamps in an audio store with a friend. I could
tell they sounded a little different, but I was unable to tell exactly what was
different or decide which one I thought sounded better for my frined to
purchase. Today, after 20 or so years experience comparing differences in
audio components I would be much more likely to be able identify and qualify
the differences.

In research, subjects get training in learning to hear the specific artifact
they are supposed to identify. Since the differences with audio equipment can
be so many different things (timbre, dynamics, soundstaging, bass, etc.) how do
you train a subject adequetly?

So I ask, if we were to set up a double blind cable
discrimination test and prior to running the test, had each testor engage in
some ABX training and we subsequently charted their sensitivity to known
types of distortions, would you conclude that the ensuing cable test would
be valid even if all testors failed to discriminate between the cables?


No, subject training is only one of the many necessary variables. What about
demonstrating the actual sensitivity of the test source material (i.e.0.5dB or
5.0dB) before applying it to a situation where the amount of audible difference
is unknown. If the audible difference is 2dB and the test is only sensitive to
5dB, then you will get null results, as most do.
Regards,
Mike