From: shetline@bbn.com (Kerry Shetline)
Newsgroups: rec.audio
Subject: Re: polarity inversion
Followup-To: rec.audio
Date: 1 Jan 1993 02:43:17 GMT
Organization: BBN
Distribution: world
NNTP-Posting-Host: bbn.com

In article <1hvai7INNt2c@transfer.stratus.com>, rsud@sw.stratus.com (Rajiv
Sud) wrote:
> 
> In article <shetline-311292015736@128.89.19.85>, shetline@bbn.com (Kerry Shetline) writes:
> > 
> > Sound waves in air consist of radiating patterns of compression and
> 	.
> 	.	<lots of crap deleted>
> 	.
> 
> Kerry,
> 	Absolute phase does matter and is easy to hear. You and other
> non-belivers might try it for yourself on something better than a mass
> market system. Better than mass market is the key (but spare me the
> arguements about not being able to afford $2000 components. If mass
> consumers weren't so complacent and demanded better they'd get it).

Given that flaws in component design are the likeliest source of
differences in sound caused by absolute phase, the more expensive stuff
should reveal polarity inversion to a lesser degree.

As for the price of the equipment, there seems to be a fairly good
correlation between money spent and the ability to convince oneself of
one's incredible capacity to discern subtle effects that the poorer rabble
can't hear. This is the kind of psychology that high-end audio dealers
depend upon. Not only can people purchase their own golden ears by spending
$3000 each on a pair of mono tube amps, but they wouldn't dare sully the
illusion by imagining that a few dollars worth of 18-gauge wire from Radio
Shack could conduct the magic flow of music to their mortgage-busting
speakers nearly as well as $300 pieces of copper snake-oil.

If you don't believe in your mind's ability to affect the way things sound,
consider this experience common to nearly all of us: You hear a song, but
you can't make out the lyrics. Later, you finally figure them out, somebody
else tells you, or you read the lyrics. From then on, when you hear the
song the words sound like they are supposed to sound. I don't mean that the
words are simply more intelligible -- THEY SOUND DIFFERENT. The effect is
entirely in the brain's processing, not in the signal.

The reason for this comes from the nature of the task that the ear and
brain must perform to parse sound and music. The ear receives a jumble of
frequency components from separate sources simultaneously, and the brain
must discern which components are related and identify the source. To
exaggerate the dillema, suppose I gave you the number 42, and said that it
was obtained as the sum of a set of numbers, and asked you to guess the
set. There is no way for you to reasonably approach the problem without
some expectations as to the number of items in the set, and without good
guesses for most of those items.

As I said, this is an exaggeration, but the analogy holds. Hearing requires
active application of expectation to processing, probably more than any
other sense. This is why it is quite possible for some people to REALLY
HEAR differences in sounds that are created, quite literally, inside their
heads -- all the more reason why people should demand, of themselves as
well as others, objective testing. Note that I don't say explanations. It
is possible for a thing to be without complete explanation (e.g. the exact
effect of aspirin on body chemistry and the neural system) but objectively
testable (clinical trials with control groups).

Usually, however, there should at least be hints as to the mechanism for a
phenomemon, and certainly one should always beware of devices and dubious
procedures that must always creep out of the light of explanation to hide
in the camouflage of the unknown.

-Kerry
Newsgroups: rec.audio