"Mark DeBellis" wrote in message
...
On 16 Jun 2005 23:53:16 GMT, "Ban" wrote:
Gary Eickmeier wrote:
Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.
I second Garys comment. Some additions:
There are ABX switchboxes available, I made one myself with relays to
switch
between two speaker cables simultaneously on both ends. You can switch any
time as much as you like.
Sorry I guess I didn't explain my idea very well. Suppose that in
order to perceive the relevant property a listener has to hear an
uninterrupted stretch of music from the same source. That is, suppose
the relevant property is not a property that belongs to any short
snippet of the signal but is rather a property that belongs only to a
whole, longer passage, say 5 mins. in length or a whole movement.
What I am thinking of here is the SACD vs. CD issue discussed on
another thread. I am wondering if the unit over which perception can
differ meaningfully can be an extended passage not a brief interval;
if so, my switching back and forth between SACD and CD would not be a
relevant test, because I would hear neither SACD nor CD as an unbroken
extended passage. I guess I am asking basically whether the existing
protocols for audio tests make room for the possibility that there can
be auditory perception of properties of longer, extended passages, and
are sufficient to measure such perception.
Perhaps the answer would be that there could not be a difference in
perceptible properties of longer passages without a detectable
difference in frequency response, which could be heard in quick-switch
tests; but is that obvious?
There is a very simple, very powerful way to determine this. But it is not
practical or possible for one individual. It is called monadic testing. It
requires listening to the segment of music, and rating that musical
reproduction *immediately afterwards* using a series of rating criteria.
Such criteria might include, for example, a five point scale ranging from:
"bass sounded extrememly punchy" to "bass sounded flabby and undynamic".
When hundreds of people do this, statistics can be applied to determine if
there are in fact perceivable differences, and if so, on what criteria.
If I were Harmon Industries, I might design and sponsor such a test on
occasion. Frankly, Sony blew an opportunity to do such a test (it would be
expensive) for their SACD launch. Imagine if the introductory campaign had
included "proof" that SACD sounded better. We'd now have a viable second
format.
If I were the AES, I might sponsor such a test as a "control test" for
single-person tests such as the much bally-hooed ABX test, to advance the
state of the art..
But for a given individual it is not a practical test.
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