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44.1 vs 88.2 ABX report at AES
2Bdecided
post Jul 16 2010, 17:07
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Here:

http://www.aes.org/events/128/papers/?ID=2252

QUOTE
P18-6 Sampling Rate Discrimination: 44.1 kHz vs. 88.2 kHz—Amandine Pras, Catherine Guastavino, McGill University - Montreal, Quebec, Canada
It is currently common practice for sound engineers to record digital music using high-resolution formats, and then down sample the files to 44.1 kHz for commercial release. This study aims at investigating whether listeners can perceive differences between musical files recorded at 44.1 kHz and 88.2 kHz with the same analog chain and type of AD-converter. Sixteen expert listeners were asked to compare 3 versions (44.1 kHz, 88.2 kHz, and the 88.2 kHz version down-sampled to 44.1 kHz) of 5 musical excerpts in a blind ABX task. Overall, participants were able to discriminate between files recorded at 88.2 kHz and their 44.1 kHz down-sampled version. Furthermore, for the orchestral excerpt, they were able to discriminate between files recorded at 88.2 kHz and files recorded at 44.1 kHz.
Convention Paper 8101


Was anyone at the presentation? Has anyone bought the paper?

Cheers,
David.
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amandinepras
post Jul 19 2010, 00:52
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Thanks all for your interest in our paper,
I received an invitation from hydrogenaudio to provide further details on our work.
Thus I will do my best to answer a few questions I could extract from the discussion.

- We used Pyramix 6.0 for down-sampling, as this software is currently used by a lot of audio professionals who produce HD recordings.
- Regarding the statistics, the "p" we provided for the results refers to the probability that we got the result by chance. Traditionally for this kind of test (here an ABX), researchers consider that if p<.05, the result is not obtained by chance (as the probability is below 5%), thus participants could discriminate. If .05<p<.1, it may be that the result was not obtained by chance but it's not for sure, that's what is called "a tendency".
If the test was easy, we would not need statistics, as participants would have almost 100% of good answers. But this test was extremely challenging for the expert listeners, implying a lot of errors even if some of them could perceive some differences between formats in specific cases (musical excerpt, type of format comparison).
- There is no proof that upsampling doesn't introduce artifacts.
- Regarding our choice of format comparison and technical chain, our purpose was to investigate perceptive differences between 88.2 vs. 44.1 in "real-life" use of the equipment, thus by taking into consideration what happens in music production and release: in a few cases, music is produced and released in high-resolution (thus playback in high-resolution); in more cases, music is produced in high-resolution and then down-sample into 44.1 for commercial release (thus playback in 44.1); in a lot of cases, music is produced and released in 44.1 (thus playback in 44.1).
We used the Fireface DAC as it was the only one that allowed us to switch sample rate with a reasonable delay for the test (less than 1sec.). I wish we could use a better one. However, the Fireface is still pretty good compared to most playback systems people use in their house.

I am a sound engineer myself and started working in research as a part time job 3 years ago. I was glad to work on the high-resolution project as I have heard a lot of discussions in studios and during my sound recording studies on the topic. My main question was if it was worth working in High-Res when the project was to be released in 44.1.
This AES paper is the first publication for this study and provides a few answers, maybe not enough for most of us. There will be more stuff coming up. And maybe other labs will work on that topic too as they are A LOT of tests to be done.

Bottom line, although the topic is interesting, mainly these days when the Blue Ray Pure Audio is to be defined, never forget that differences between formats, ADC, DAC,... remain extremely subtle compared to differences between miking techniques, room acoustics, and of courses musicians and their instruments!
Best,
Amandine
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hciman77
post Jul 28 2010, 15:18
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QUOTE (amandinepras @ Jul 18 2010, 19:52) *
Thanks all for your interest in our paper,
I received an invitation from hydrogenaudio to provide further details on our work.
Thus I will do my best to answer a few questions I could extract from the discussion.

- We used Pyramix 6.0 for down-sampling, as this software is currently used by a lot of audio professionals who produce HD recordings.
- Regarding the statistics, the "p" we provided for the results refers to the probability that we got the result by chance. Traditionally for this kind of test (here an ABX), researchers consider that if p<.05, the result is not obtained by chance (as the probability is below 5%), thus participants could discriminate. If .05<p<.1, it may be that the result was not obtained by chance but it's not for sure, that's what is called "a tendency".
If the test was easy, we would not need statistics, as participants would have almost 100% of good answers. But this test was extremely challenging for the expert listeners, implying a lot of errors even if some of them could perceive some differences between formats in specific cases (musical excerpt, type of format comparison).
- There is no proof that upsampling doesn't introduce artifacts.
- Regarding our choice of format comparison and technical chain, our purpose was to investigate perceptive differences between 88.2 vs. 44.1 in "real-life" use of the equipment, thus by taking into consideration what happens in music production and release: in a few cases, music is produced and released in high-resolution (thus playback in high-resolution); in more cases, music is produced in high-resolution and then down-sample into 44.1 for commercial release (thus playback in 44.1); in a lot of cases, music is produced and released in 44.1 (thus playback in 44.1).
We used the Fireface DAC as it was the only one that allowed us to switch sample rate with a reasonable delay for the test (less than 1sec.). I wish we could use a better one. However, the Fireface is still pretty good compared to most playback systems people use in their house.

I am a sound engineer myself and started working in research as a part time job 3 years ago. I was glad to work on the high-resolution project as I have heard a lot of discussions in studios and during my sound recording studies on the topic. My main question was if it was worth working in High-Res when the project was to be released in 44.1.
This AES paper is the first publication for this study and provides a few answers, maybe not enough for most of us. There will be more stuff coming up. And maybe other labs will work on that topic too as they are A LOT of tests to be done.

Bottom line, although the topic is interesting, mainly these days when the Blue Ray Pure Audio is to be defined, never forget that differences between formats, ADC, DAC,... remain extremely subtle compared to differences between miking techniques, room acoustics, and of courses musicians and their instruments!
Best,
Amandine


Many thanks for your reply, is there any chance we could get access to the raw data ?


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Posts in this topic
- 2Bdecided   44.1 vs 88.2 ABX report at AES   Jul 16 2010, 17:07
- - Dologan   Interesting. The fact that the discrimination was ...   Jul 16 2010, 18:18
|- - C.R.Helmrich   http://coltrane.music.mcgill.ca/MAQ/experiments co...   Jul 16 2010, 19:33
|- - Dologan   QUOTE (C.R.Helmrich @ Jul 16 2010, 19:33)...   Jul 16 2010, 20:30
- - Arnold B. Krueger   QUOTE (2Bdecided @ Jul 16 2010, 12:07) He...   Jul 16 2010, 19:45
|- - pbelkner   QUOTE (Arnold B. Krueger @ Jul 16 2010, 20...   Jul 16 2010, 20:01
||- - Dologan   QUOTE (pbelkner @ Jul 16 2010, 20:01) QUO...   Jul 16 2010, 20:03
||- - pbelkner   QUOTE (Dologan @ Jul 16 2010, 21:03) but ...   Jul 16 2010, 20:19
||- - benski   Yes, exactly. It is cheaper to design a 192kHz DA...   Jul 16 2010, 20:47
||- - Arnold B. Krueger   QUOTE (Dologan @ Jul 16 2010, 15:03) QUOT...   Jul 16 2010, 23:21
|- - C.R.Helmrich   QUOTE Overall, participants were able to discrimin...   Jul 16 2010, 20:25
|- - pbelkner   QUOTE (C.R.Helmrich @ Jul 16 2010, 21:25)...   Jul 16 2010, 20:59
- - krabapple   1) I suggest this thread be focused on the 44.1 v...   Jul 16 2010, 22:23
|- - WernerO   QUOTE (krabapple @ Jul 16 2010, 23:23) Th...   Aug 11 2010, 13:51
|- - mzil   QUOTE (krabapple @ Jul 16 2010, 17:23) 2)...   Jul 22 2012, 02:47
|- - C.R.Helmrich   Sorry for bumping this thread, but I thought the f...   Mar 8 2014, 01:21
|- - [JAZ]   QUOTE (C.R.Helmrich @ Mar 8 2014, 01:21) ...   Mar 8 2014, 18:38
- - googlebot   Why upsample? 99.9% of all DACs oversample anyway....   Jul 16 2010, 22:25
|- - Arnold B. Krueger   QUOTE (googlebot @ Jul 16 2010, 17:25) Wh...   Jul 16 2010, 23:47
|- - benski   QUOTE (Arnold B. Krueger @ Jul 16 2010, 18...   Jul 17 2010, 03:12
||- - Arnold B. Krueger   QUOTE (benski @ Jul 16 2010, 22:12) QUOTE...   Jul 17 2010, 06:39
||- - greynol   QUOTE (Arnold B. Krueger @ Jul 16 2010, 22...   Jul 17 2010, 18:33
||- - Arnold B. Krueger   QUOTE (greynol @ Jul 17 2010, 13:33) QUOT...   Jul 17 2010, 20:35
|- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jul 16 2010, 23...   Jul 21 2010, 13:22
- - Alex B   I think the least incorrect way to compare 88.2 KH...   Jul 16 2010, 22:33
|- - Arnold B. Krueger   QUOTE (Alex B @ Jul 16 2010, 17:33) I thi...   Jul 16 2010, 23:30
|- - Dologan   QUOTE (Alex B @ Jul 16 2010, 22:33) I thi...   Jul 16 2010, 23:40
- - AndyH-ha   It seems that what I wrote in the first part of my...   Jul 17 2010, 09:55
|- - googlebot   AndyH-ha, that might be on purpose. For two lowpas...   Jul 17 2010, 10:49
- - googlebot   I think the 88.2 vs. downsampled 44.1 test had at ...   Jul 17 2010, 16:39
- - greynol   QUOTE (Arnold B. Krueger @ Jul 17 2010, 12...   Jul 17 2010, 20:48
|- - Arnold B. Krueger   QUOTE (greynol @ Jul 17 2010, 15:48) QUOT...   Jul 17 2010, 23:04
- - AndyH-ha   I also may not know what I'm talking about, bu...   Jul 17 2010, 22:02
- - greynol   The reason for oversampling in old CD players is a...   Jul 17 2010, 22:13
|- - Arnold B. Krueger   QUOTE (greynol @ Jul 17 2010, 17:13) The ...   Jul 17 2010, 23:14
- - greynol   I'm taking issue with what I thought was a bla...   Jul 17 2010, 23:27
|- - Arnold B. Krueger   QUOTE (greynol @ Jul 17 2010, 18:27) I...   Jul 18 2010, 01:52
|- - greynol   QUOTE (Arnold B. Krueger @ Jul 17 2010, 17...   Jul 19 2010, 00:56
- - amandinepras   Thanks all for your interest in our paper, I recei...   Jul 19 2010, 00:52
|- - Arnold B. Krueger   QUOTE (amandinepras @ Jul 18 2010, 19:52)...   Jul 19 2010, 03:35
|- - Arnold B. Krueger   QUOTE (amandinepras @ Jul 18 2010, 19:52)...   Jul 19 2010, 11:35
||- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jul 19 2010, 11...   Jul 21 2010, 13:20
||- - Kees de Visser   QUOTE (2Bdecided @ Jul 21 2010, 14:20) QU...   Jul 23 2010, 09:26
|- - Arnold B. Krueger   QUOTE (amandinepras @ Jul 18 2010, 19:52)...   Jul 19 2010, 11:48
||- - googlebot   QUOTE (Arnold B. Krueger @ Jul 19 2010, 12...   Jul 19 2010, 12:19
|||- - Arnold B. Krueger   QUOTE (googlebot @ Jul 19 2010, 07:19) QU...   Jul 19 2010, 14:33
||- - krabapple   QUOTE (Arnold B. Krueger @ Jul 19 2010, 06...   Jul 19 2010, 14:08
|- - Notat   QUOTE (amandinepras @ Jul 18 2010, 17:52)...   Jul 21 2010, 04:08
|- - hciman77   QUOTE (amandinepras @ Jul 18 2010, 19:52)...   Jul 28 2010, 15:18
- - Pio2001   Thanks for joining the discussion, Amandine. Your...   Jul 19 2010, 12:31
|- - 2Bdecided   QUOTE (Pio2001 @ Jul 19 2010, 12:31) I se...   Jul 21 2010, 13:13
- - googlebot   The study shows at least the intent of objectivity...   Jul 19 2010, 16:28
|- - Arnold B. Krueger   QUOTE (googlebot @ Jul 19 2010, 11:28) [l...   Jul 19 2010, 19:11
|- - Soap   QUOTE (Arnold B. Krueger @ Jul 19 2010, 14...   Jul 19 2010, 20:24
|- - Soap   QUOTE (Arnold B. Krueger @ Jul 19 2010, 14...   Jul 19 2010, 23:07
- - Juha   QUOTE Doesn't anybody else see a problem with ...   Jul 19 2010, 19:25
- - googlebot   The manufacturer's specs for the FF 800. Unwei...   Jul 19 2010, 20:22
|- - Arnold B. Krueger   QUOTE (googlebot @ Jul 19 2010, 15:22) Th...   Jul 19 2010, 21:26
- - Cavaille   Forgive me to interrupt this discussion about the ...   Jul 20 2010, 08:40
|- - Arnold B. Krueger   QUOTE (Cavaille @ Jul 20 2010, 03:40) Arn...   Jul 20 2010, 13:13
|- - Arnold B. Krueger   QUOTE (Arnold B. Krueger @ Jul 20 2010, 08...   Jul 20 2010, 19:30
||- - Pio2001   QUOTE (Arnold B. Krueger @ Jul 20 2010, 20...   Jul 20 2010, 22:36
|||- - Arnold B. Krueger   QUOTE (Pio2001 @ Jul 20 2010, 17:36) QUOT...   Jul 20 2010, 23:57
||- - C.R.Helmrich   QUOTE (Arnold B. Krueger @ Jul 20 2010, 20...   Jul 20 2010, 22:53
|- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jul 20 2010, 13...   Jul 21 2010, 13:25
|- - WernerO   QUOTE (Arnold B. Krueger @ Jul 20 2010, 14...   Aug 2 2010, 08:19
|- - Arnold B. Krueger   QUOTE (WernerO @ Aug 2 2010, 03:19) QUOTE...   Aug 2 2010, 11:56
- - Pio2001   The strange thing is that there are ABX results wi...   Jul 21 2010, 12:16
|- - hciman77   QUOTE (Pio2001 @ Jul 21 2010, 07:16) The ...   Jul 27 2010, 22:56
- - googlebot   The fact, that the study's authors have regist...   Jul 23 2010, 10:55
|- - Pio2001   QUOTE (googlebot @ Jul 23 2010, 11:55) co...   Jul 24 2010, 13:58
- - krabapple   Sheesh, it's only been four days. They may ac...   Jul 23 2010, 19:20
- - googlebot   In dubio pro reo is generally a good principle. Bu...   Jul 26 2010, 19:43
|- - hciman77   QUOTE (googlebot @ Jul 26 2010, 14:43) In...   Jul 26 2010, 21:05
- - hciman77   I read the full paper and I think there may be som...   Jul 26 2010, 19:48
|- - Arnold B. Krueger   QUOTE (hciman77 @ Jul 26 2010, 14:48) I r...   Jul 27 2010, 13:16
||- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jul 27 2010, 13...   Jul 27 2010, 22:45
|- - Pio2001   QUOTE (hciman77 @ Jul 26 2010, 20:48) Thi...   Jul 28 2010, 11:39
|- - Arnold B. Krueger   QUOTE (Pio2001 @ Jul 28 2010, 06:39) QUOT...   Jul 28 2010, 13:52
|- - AndyH-ha   QUOTE (Arnold B. Krueger @ Jul 28 2010, 04...   Jul 28 2010, 22:42
|- - Arnold B. Krueger   QUOTE (AndyH-ha @ Jul 28 2010, 17:42...   Jul 29 2010, 13:04
|- - 2Bdecided   QUOTE (AndyH-ha @ Jul 28 2010, 22:42...   Jul 29 2010, 22:11
|- - SebastianG   QUOTE (2Bdecided @ Jul 29 2010, 22:11) bu...   Jul 30 2010, 09:55
|- - Arnold B. Krueger   QUOTE (2Bdecided @ Jul 29 2010, 17:11) I ...   Jul 30 2010, 12:26
- - lvqcl   Audition 1.5: 44.1 -> 96 kHz resampling, Qualit...   Jul 30 2010, 11:42
- - C.R.Helmrich   I finally found time to read the entire paper. It...   Aug 9 2010, 21:41
- - 2Bdecided   I think before you pull out one positive result an...   Aug 9 2010, 22:44
|- - C.R.Helmrich   QUOTE (2Bdecided @ Aug 9 2010, 23:44) I t...   Aug 10 2010, 01:37
- - Pio2001   I finaly got the article. Actually, they say somet...   Aug 9 2010, 23:33
- - Pio2001   The unknown thing is the origin of the p values. I...   Aug 10 2010, 12:33
- - lrossouw   Did they test for difference (Check if you can tel...   Sep 8 2010, 09:39
- - Mach-X   I am going to loosely quote a well known poster he...   Mar 8 2014, 08:08
|- - Arnold B. Krueger   QUOTE (Mach-X @ Mar 8 2014, 03:08) I...   Mar 10 2014, 12:58
- - bandpass   TEAC -- slight COI perhaps? Guessing their method...   Mar 8 2014, 09:06
- - WernerO   Perhaps. Another weakness is their apparent use o...   Mar 11 2014, 08:04
|- - Arnold B. Krueger   QUOTE (WernerO @ Mar 11 2014, 03:04) Perh...   Mar 11 2014, 13:44
||- - Kees de Visser   QUOTE (Arnold B. Krueger @ Mar 11 2014, 13...   Mar 11 2014, 14:28
|- - C.R.Helmrich   QUOTE (WernerO @ Mar 11 2014, 08:04) Anot...   Mar 11 2014, 23:55
- - Wombat   QUOTE (Kees de Visser @ Mar 11 2014, 14:2...   Mar 11 2014, 15:51
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