[Audio Empire]

On Sun, 17 Oct 2010 09:11:33 -0700, Arny Krueger wrote
(in article ):

"Audio Empire" wrote in message


Mmmmm. Are you sure that perceptual coding produces
linear distortion?

Yes.

I thought linear distortion was a
filter function where gain (or delay) varies with
frequency.

Perceptual coders are lagely based on filter banks.



MMMM, I didn't realize that they worked that way. Makes sense, I guess.

[Audio Empire]

On Fri, 15 Oct 2010 11:38:20 -0700, H Davis wrote
(in article ):

"Audio Empire" wrote in message=20
...
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snip
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Massenburg then used a demonstration to drive his point home. He
electronically subtracted the MP3 compressed music from the original
24-bit/96 KHz recording and then played ONLY the difference signal whi=
ch=20
was
comprised solely of the information lost by the compression.
=20
"These are distortion levels of 15 =EF=BF=BD 20 percent! ", he said as=
he played=20
the
difference signal for all to hear. The distortion amazed everyone in
attendance because it was a grotesquely, but very recognizable version=
of=20
the
original recoding!
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He went on to say that while AAC was clearly better than MP3, it still
generated 5% to 10% distortion.
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snip
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I have just one question. If indeed distortion levels of the magnitudes=
=20
quoted above are present, WHY ARE THEY NOT AUDIBLE? One can certainly h=
ear=20
even one or two percent harmonic distortion.=20
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They are audible.=20