Posted by
Hemos
on from the learn-more-about-it dept.
bullitB writes "For fans of the world wide patent conspiracy's latest audio format, the latest double blind AAC encoder comparison test results are in. If nothing else, this suggests much of the complaints regarding the iTunes Music Store's lossyness might be unfounded."
Re:iTMS music does NOT sound lossy
by
misterpies
·
· Score: 5, Informative
I can tell you're a medical student and not a doctor, because most doctors are much more realistic about the limits of their knowledge. "Scientific" limits on the capabilities of biological systems are often wrong because of some overlooked or unknown factor.
A famous example of this is that for many years scientists could not work out how bees could fly. Their wings were too small, muscles too weak and bodies too heavy. It turned out that bees were able to use previously unknown aerodynamic effects to generate more lift than our previous "knowledge" allowed. Another example is that many birds of prey have visual acuity better than the laws of optics, applied to their eyes, would seem to permit. It turned out that the visual signal processing in their brains is so advanced that birds can actually 'see' features that are below the resolution limit of their eyes.
Similarly, we shouldn't be too dogmatic about what humans can and cannot hear. MP3s (and presumably AACs) compress music by suppressing parts you "can't" hear, not because they're outside your range of hearing but because the brain, assuming those parts should be there, fills in for them even when they're absent.
But it may be that you can't hear something consciously but still tell that it's not there. For example, there was a news story a week or so back showing that people could somehow tell when a picture had changed by the removal of an item in it, even though consciously they could not explain what the difference was - it just 'felt different'.
So, if someone claims to be able to tell the difference between 1 128Kb AAC and a CD, test that claim in a double-blind experiment. Only when he fails the test can you say he was imagining things.
-- The author of this post asserts his moral rights.
Unfortunately...
by
lotsofno
·
· Score: 5, Informative
Winamp 5.02's encoder (which got a lot of help from hydrogenaudio's own Menno, a FAAD AAC-decoder developer/Ahead MPEG4 developer) wasn't included in the listening test because of a bug they found before testing.
Too bad, too. I would've loved to have seen how it compared.
Re:I'm not a doctor, but I play one on television
by
Golias
·
· Score: 5, Informative
The parent to this post was modded down for being rude to the grandparent, I suppose... but the point was correct. "The Digital Sound," as we used to call it back in the 80s, turned out to be the result of poor D/A conversion, poor error correction, and amplification hardware that was tweaked to compensate the shortcomings of LPs. Like I mentioned on another audio-related thread last week, a $300 Rotel CD player connected to a modern high-end stereo will sound as good or better when compared to a $3000 air-suspended, laser-guided turntable. (Especially after the LP has been played a few dozen times.)
--
Information wants to be anthropomorphized.
Re:Error bars
by
patman600
·
· Score: 5, Informative
As a high school senior in a Statistics AP class currently studying confidence intervals and hypothesis testing, I think you are missing something. At the beginning, he clearly states your point: "One codec can be said to rated better than another codec with 95% confidence if the bottom of its line segment is at or above the top of the competing codec's line segment." The author gives which one is in first place, but announces at the beginning the requirements for a clear winner. And the author seems to me to be requiring at least half an interval of difference to even say that, much of the time he says they are tied.
Re:You may have a point
by
BorgCopyeditor
·
· Score: 5, Informative
They may be pricks (or trolls), but they have some good points. If you can get past the annoying exterior, you might find some good information on these issues by googling for "audiophile" in rec.audio.pro, a group populated primarily by very good recording engineers. These are guys (mostly) who got where they are through both excellent (and aesthetically attuned) hearing and scientific knowledge of how audio works at every point in the signal chain. To watch them dismiss, with unimpeachable arguments and long experience, the claims of "sensitive" audiophiles can be instructive. I speak as one who has been schooled.
Slashdot Mirror
You can discuss this test with the author and others at http://www.hydrogenaudio.org
here
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c =1 3464&
http://www.rjamorim.com/test/64test/results.htm
and here
http://www.hydrogenaudio.org/index.php?showtopi
I can tell you're a medical student and not a doctor, because most doctors are much more realistic about the limits of their knowledge. "Scientific" limits on the capabilities of biological systems are often wrong because of some overlooked or unknown factor.
A famous example of this is that for many years scientists could not work out how bees could fly. Their wings were too small, muscles too weak and bodies too heavy. It turned out that bees were able to use previously unknown aerodynamic effects to generate more lift than our previous "knowledge" allowed. Another example is that many birds of prey have visual acuity better than the laws of optics, applied to their eyes, would seem to permit. It turned out that the visual signal processing in their brains is so advanced that birds can actually 'see' features that are below the resolution limit of their eyes.
Similarly, we shouldn't be too dogmatic about what humans can and cannot hear. MP3s (and presumably AACs) compress music by suppressing parts you "can't" hear, not because they're outside your range of hearing but because the brain, assuming those parts should be there, fills in for them even when they're absent.
But it may be that you can't hear something consciously but still tell that it's not there.
For example, there was a news story a week or so back showing that people could somehow tell when a picture had changed by the removal of an item in it, even though consciously they could not explain what the difference was - it just 'felt different'.
So, if someone claims to be able to tell the difference between 1 128Kb AAC and a CD, test that claim in a double-blind experiment. Only when he fails the test can you say he was imagining things.
The author of this post asserts his moral rights.
You mean FLAC.
FAAC is another AAC codec.
Winamp 5.02's encoder (which got a lot of help from hydrogenaudio's own Menno, a FAAD AAC-decoder developer/Ahead MPEG4 developer) wasn't included in the listening test because of a bug they found before testing.
Too bad, too. I would've loved to have seen how it compared.
The parent to this post was modded down for being rude to the grandparent, I suppose... but the point was correct. "The Digital Sound," as we used to call it back in the 80s, turned out to be the result of poor D/A conversion, poor error correction, and amplification hardware that was tweaked to compensate the shortcomings of LPs. Like I mentioned on another audio-related thread last week, a $300 Rotel CD player connected to a modern high-end stereo will sound as good or better when compared to a $3000 air-suspended, laser-guided turntable. (Especially after the LP has been played a few dozen times.)
Information wants to be anthropomorphized.
As a high school senior in a Statistics AP class currently studying confidence intervals and hypothesis testing, I think you are missing something. At the beginning, he clearly states your point: "One codec can be said to rated better than another codec with 95% confidence if the bottom of its line segment is at or above the top of the competing codec's line segment." The author gives which one is in first place, but announces at the beginning the requirements for a clear winner. And the author seems to me to be requiring at least half an interval of difference to even say that, much of the time he says they are tied.
They may be pricks (or trolls), but they have some good points. If you can get past the annoying exterior, you might find some good information on these issues by googling for "audiophile" in rec.audio.pro, a group populated primarily by very good recording engineers. These are guys (mostly) who got where they are through both excellent (and aesthetically attuned) hearing and scientific knowledge of how audio works at every point in the signal chain. To watch them dismiss, with unimpeachable arguments and long experience, the claims of "sensitive" audiophiles can be instructive. I speak as one who has been schooled.
Shop as usual. And avoid panic buying.