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The Emperor's New Sample Rate, MIX magazine wonders if "maybe CD is good enough"
Pio2001
post May 1 2008, 14:40
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QUOTE (greynol @ May 1 2008, 01:32) *
In this study, people that got high scores were re-tested and failed. If they could truly hear a difference then they would have been able to repeat their high scores.


No, there were no high scores at all, as Krabapple said above :

QUOTE (krabapple @ Apr 24 2008, 17:14) *
Third, I misremembered. In fact, there was no retesting...because no subject achieved a score where p< 0.05, unless levels were jacked up to abnormal levels.


Thus retesting was not needed. Which answers 2tec original question : both average results and individual results were taken into account. There was no positive result.

In the Detmold university listening test, 200 listeners took the same challenge. Some scored above the significance threshold, but this was coherent with random guessing at the collective level.
However, one of them got a score of 20/20, which is significant even in a collective test with 200 listeners.
The authors said that unfortunately, a small noise at the beginning of one of the samples, though unheard by the listeners, may have biased the result.
Maybe also this listener really hears ultrasounds... I don't remember the study talking about his or her hearing ability in high frequencies.
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lexor
post May 1 2008, 16:39
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QUOTE (krabapple @ Apr 25 2008, 02:00) *
Don't know about that....perhaps we should both review the HA archive. My memory is that a very few savants like gurubroolz are so attuned to mp3 artifacts that they CAN often ABX them, even at high CBR or VBR with the best LAME codecs...far more routinely than the average punter. It would not be surprising if mp3 codec tweakers were blessed/cursed with this talent. It would be surprising if a typically 40-ish mp3-denouncing 'audiophile' writing for Stereophile, could truly do the same

Guru ABXed artifacts of mp3, especially on low volume classical and natural instrument music. I think I have followed all of his ABX threads and I don't recall anything about him ABXing frequencies. Ability to ABX an mp3 vs CD doesn't mean it is the frequency that you can distinguish. In fact with all (pre)echo and such artifacts with mp3, higher frequencies are probably the least noticeable/contributing factor.

This post has been edited by lexor: May 1 2008, 16:40


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AndyH-ha
post May 1 2008, 22:04
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QUOTE
However, using such an 'unfair' derivation method (Audacity software), I was easily able to ABX (with foobar) the sound of a triangle being struck


All resampling is not equal. Compare the Adobe Audition Sweep tone resampling (using proper pre/post filters, or even without the filters) against that of Gold Wave for an easy explanation. Audacity (High-quality Sinc Interpolation) is significantly worse.
http://src.infinitewave.ca/

The resampled triangle sample from Audacity isnít quite so colorful as the resampled sweep tone, but when comparing Audacityís result to CoolEdit resampling (the precursor to Audition, for those who donít know), the visual differences, especially in the critical midbands, are very obvious.
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greynol
post May 1 2008, 22:07
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In situations like this I think it's worth mentioning (again) that your soundcard may be resampling during these listening tests as well.


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cabbagerat
post May 2 2008, 07:04
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QUOTE (AndyH-ha @ May 1 2008, 13:04) *
The resampled triangle sample from Audacity isnít quite so colorful as the resampled sweep tone, but when comparing Audacityís result to CoolEdit resampling (the precursor to Audition, for those who donít know), the visual differences, especially in the critical midbands, are very obvious.
The resampling quality in Audacity, when I tested it, was rather poor. I initially thought it was using libsamplerate (secret rabbit code), but apparently the use another library, based on the same algorithm, due to some licensing issues. Libsamplerate 0.1.3 works very well, and should give excellent results, and you can build audacity on Linux to link against it.


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AndyH-ha
post May 2 2008, 11:17
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I mentioned the visual differences due to Audacity's poor resampling, since not everyone has decent analysis software. The auditory differences in the triangel sample are so striking that anyone should be able to hear them, no special software required.

Playing with Audacity a little, I found something rather strange, or maybe not too strange as I havenít had reason to investigate other programs since CoolEdit does such an excellent job.

Originally I generated a sweep tone in CoolEdit at 96kHz (100Hz to 48kHz Sine wave over 10 seconds). I just modified some settings Iíd used some time ago. The Sine wave was modulated. I donít remember the Modulated By value but the Modulation Frequency was 10Hz. Resampled in Audacity, this produced a very colorful Spectral View showing much harmonic distortion, aliasing, and spurious frequencies.

Afterwards I generated the same sweep tone without any modulation, as pure a sine wave as CoolEdit can generate. The Audacity resampling Spectral View of that looks almost like the CoolEdit resampling, very different than the modulated sweep tone. While neither are music, I would say the modulated tone is more representative of most music.

This post has been edited by AndyH-ha: May 2 2008, 11:18
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krabapple
post May 2 2008, 20:29
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QUOTE (digital @ May 1 2008, 02:14) *
I don't suppose that there are any musicians Ďout thereí willing to record a minute or so of music with 24-bit and 16-bit sample rates, and then present the tracks for us to ABX? It might be something as simple as playing back a pre-recorded sample (like karaoke background music), and then doing a recording in the two formats.

It would appear to be better to do a live take Ė but there is no way that a musician(s) could do it exactly the same way twice. If anyone is interested, I'll offer to host the tracks on my server. Lemme' know - it might go a long way towards assisting in a resolution to this discussion.

Andrew D.
www.cdnav.com




Two different performances would definitely invalidate the test, and the only other means to compare the same recording without introducing heinous variables, is to either dither the 24 to 16, or record a live performance with two A/D converters, one set to 16bit and one to 24, from the same microphone input, at the same sample rate.

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porky_pig_jr
post May 2 2008, 20:47
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Regarding 16 vs 24 bits. I remember reading that our hearing distinguishes the differences at 18 bits resolution but no more, so 16 bits is a bit too low but 24 bits is simply an overkill. With a proper dithering, though, 16 bits is 'about as good as' 18 bits. I guess that does mean that Red Book format is sufficiently close to our hearing threshold in terms of resolution. In terms of sampling rate, 44.1Khz providing 22 Khz of bandwidth is more than enough.
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Jebus
post May 2 2008, 21:07
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You know what, I'll do this tonight or tomorrow... rip a 24-bit/48kHz DVD track (it'll be Sonic Youth, because its the only LPCM concert DVD I have) and then provide samples at:

24/48
16/48
24/44.1
16/44.1

I'll use SSRC and dither w/noise shaping for the 16-bit versions.

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Pio2001
post May 3 2008, 00:58
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This high resolution track is free : http://www.hydrogenaudio.org/forums/index....showtopic=35624

Working link through Megaupload, post 31, page 2.
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MLXXX
post May 3 2008, 08:47
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QUOTE (Pio2001 @ May 3 2008, 09:58) *
This high resolution track is free : http://www.hydrogenaudio.org/forums/index....showtopic=35624

Working link through Megaupload, post 31, page 2.

I had a quick listen to a 44.1KHz version (which I created with Audition 3.0) but there was no obvious difference for my ears, compared with the original 96KHz version. (I have never found the sound from guitar strings easy to detect deficencies in. I am not saying there are no differences in this laid back performance between the original 96KHz version and a 44.1KHz conversion; but merely that nothing 'stuck out' when I listened to the two versions.)

When I returned to the 96Khz/24bit sample of a triangle being struck, which I commented on at post #50 above, the differences were quite stark, so that is the sound sample I have selected for closer 'amateur analysis' ...

QUOTE (AndyH-ha @ May 2 2008, 07:04) *
All resampling is not equal.


Thanks greynol, cabbagerat and AndyH for your comments.

I have now resampled the 96/24 struck triangle sound using Audition 3.0, set to maximum conversion quality (999). This has not prevented the resampled sound sounding different. I obtained the following results:

A. Original 96KHz resampled to 44.1KHz:- duller, and sound appears to come more from from the left.
B. Original 96KHz resampled to 48KHz:- duller, and sound appears to come more from the left.
C. Above version A resampled back to 96KHz:- no improvement.
D. Above version B resampled back to 96KHz:- no improvement.
E. Original 96KHz resampled to 192KHz:- the 192KHz version had a slightly brighter sound.


The differences between A, B, C or D and the original 96/24 sample were quite stark, and I did not perform ABX tests. Either factor -- change in position of the stereo image, or the loss of apparent high frequencies -- was quite noticeable.

The difference in situation E was relatively slight, so I ABXd, in order to satisfy forum guidelines. I was a little surprised to hear a difference in situation E. I had thought the filter performance in the audible range (and even a bit beyond that) would have been indistinguishable as between a sampling rate of 96KHz and a sampling rate of 192KHz.

Listening devices used
The differences could be heard using the analogue outputs of the motherboard high definition audio on a pc running running Vista, feeding speakers; and using the analogue output of an Audigy 4 card on a computer running XP, feeding headphones.

Prima facie, a struck triangle is a valid test sound, as the triangle is an instrument of a symphony orchestra. However, could there be something anomalous about the particular triange sample? For example the microphones may have been so close that phase cancellations were occurring. In an auditorium, microphones could be quite some distance away from the percussion section of the orchestra.

I feel like a fish out of water writing on this particular topic. An amateur tredding down a path that others would have investigated years ago! Is there a consensus that a sample rate above 44.1KHz can be beneficial, at least for some musical instruments?

I had always assumed there would be slight differences with a higher sampling rate, but this thread seems to challenge that.

The diffence signal
Another test I did was to subtract version C (original -> 44.1 ->96) from the original 96Kz version (using cooledit). This yielded a difference signal that sounded like a quiet version of the original file. I note that this particular type of test is independent of the precise performance of the sound card used to listen to the difference signal that cooledit computes.

I also subtracted D (original -> 48 -> 96) from the original. The result was not audible at a normal listening gain, despite the fact that when listening to the 96/24 versions separately [version D and the original 96/24 version] I could hear a difference (confirmed with a quick ABX test).

This post has been edited by MLXXX: May 4 2008, 02:31
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2tec
post May 4 2008, 01:11
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QUOTE (krabapple @ Apr 30 2008, 20:26) *
What I wrote there certainly is not even close to equivalent to writing 'no one can hear any better than anyone else', and if you can't see that, you're even more obtuse than I thought. Or you're trolling.
All I can say is that is that's how it reads to me. Perhaps it's just your insults that make your statements seem confused?
QUOTE (krabapple @ Apr 30 2008, 20:26) *
Are you suggesting that any single 16-bit process inserted into an otherwise 32-bit chain should be audible to 'golden ears' at normal levels in a blind test?
Nope, as everyone else knows, I was just wondering if they'd retested those who scored above average.
QUOTE (krabapple @ Apr 30 2008, 20:26) *
Go do some reading. You know where the links are, and you know how to get the paper. I'm not here to be your special ed teacher.
My, aren't you being especially helpful! laugh.gif


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krabapple
post May 4 2008, 01:38
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QUOTE (2tec @ May 3 2008, 20:11) *
QUOTE (krabapple @ Apr 30 2008, 20:26) *
What I wrote there certainly is not even close to equivalent to writing 'no one can hear any better than anyone else', and if you can't see that, you're even more obtuse than I thought. Or you're trolling.
All I can say is that is that's how it reads to me. Perhaps it's just your insults that make your statements seem confused?


No, I think you're just not reading carefully, or not understanding the concepts involved. I don't see anyone else here claiming to be confused by the two statements.

QUOTE
QUOTE (krabapple @ Apr 30 2008, 20:26) *
Are you suggesting that any single 16-bit process inserted into an otherwise 32-bit chain should be audible to 'golden ears' at normal levels in a blind test?

Nope, as everyone else knows, I was just wondering if they'd retested those who scored above average.


And you're still wondering, even though, 'as everyone else knows', you were informed days ago that there were no scores 'above average' (at the p<.05 level)?

Btw, your statements seem confused. Are you saying you're NOT suggesting that that a proper re-test of a putative high scorer on a DSD vs Redbook test, would be to see if they could tell 16-bit from 24-bit audio?


QUOTE
QUOTE (krabapple @ Apr 30 2008, 20:26) *

Go do some reading. You know where the links are, and you know how to get the paper. I'm not here to be your special ed teacher.
My, aren't you being especially helpful! laugh.gif


You don't seem to have exploited the help you've already been given.

This post has been edited by krabapple: May 4 2008, 01:45
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cabbagerat
post May 4 2008, 10:11
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QUOTE (MLXXX @ May 2 2008, 23:47) *
A. Original 96KHz resampled to 44.1KHz:- duller, and sound appears to come more from from the left.
B. Original 96KHz resampled to 48KHz:- duller, and sound appears to come more from the left.
C. Above version A resampled back to 96KHz:- no improvement.
D. Above version B resampled back to 96KHz:- no improvement.
E. Original 96KHz resampled to 192KHz:- the 192KHz version had a slightly brighter sound.
I don't have access to Audition. Is it possible for you to make the resampled versions available for download somewhere. From online tests, it seems as though Audition's resampling is very good. Also, try out the free version of r8brain at 44.1kHz.

QUOTE (MLXXX @ May 2 2008, 23:47) *
The differences between A, B, C or D and the original 96/24 sample were quite stark, and I did not perform ABX tests. Either factor -- change in position of the stereo image, or the loss of apparent high frequencies -- was quite noticeable.

I see three possibilities here:
  • You can hear frequencies over 20kHz.
  • Your soundcard's DAC is doing something different with different sampling rates, possibly performing resampling.
  • Your speakers/amp do something strange with high frequencies - like excessive intermodulation distortion.

QUOTE (MLXXX @ May 2 2008, 23:47) *
The difference in situation E was relatively slight, so I ABXd, in order to satisfy forum guidelines. I was a little surprised to hear a difference in situation E. I had thought the filter performance in the audible range (and even a bit beyond that) would have been indistinguishable as between a sampling rate of 96KHz and a sampling rate of 192KHz.
This makes me think that it's an effect of the resampler, and not your hearing. While it's possible you can hear frequencies above 20kHz, it's very unlikely you can hear above 44kHz. Maybe trying out r8brain is the way to go.

QUOTE (MLXXX @ May 2 2008, 23:47) *
Prima facie, a struck triangle is a valid test sound, as the triangle is an instrument of a symphony orchestra. However, could there be something anomalous about the particular triange sample? For example the microphones may have been so close that phase cancellations were occurring. In an auditorium, microphones could be quite some distance away from the percussion section of the orchestra.
A struck triangle is still a legitimate music sound, wherever it's recorded from.

QUOTE (MLXXX @ May 2 2008, 23:47) *
I feel like a fish out of water writing on this particular topic. An amateur tredding down a path that others would have investigated years ago! Is there a consensus that a sample rate above 44.1KHz can be beneficial, at least for some musical instruments?
No consensus I have come across. A lot of people have done tests (like the papers presented earlier in this thread) without statistically significant results.


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MLXXX
post May 4 2008, 19:11
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Thx cabbagerat.

Did some quick tests with r8brain at its maximum quality settings. It performed more accurately than Audition 3. For example, my new file C (96 > 44.1 > 96) could be subtracted from the original struck triangle sample and leave no audible difference signal. [I noted in my post above that Audition 3 produced quite an audible difference signal with its sample rate conversions via 44.1Khz compared with the original sample.]

Am a bit pressed for time so will mention this: I found the r8brain 44.1KHz version did sound slightly duller (with my XP computer, Audigy 4 sound card, and headphones) and this difference was ABXable.

As this could have been due merely to differences in my sound card's filtering on playback, I then opened my new version C file and the original 96/24 sample, in foobar. The converted version still sounded slightly different (as if a tone control had been used to make the converted version slighter less bright). This was ABXable.

I don't have time at the moment to do uploads but may get around to that soon and can then post again.

QUOTE (cabbagerat @ May 4 2008, 19:11) *
No consensus I have come across. A lot of people have done tests (like the papers presented earlier in this thread) without statistically significant results.
MMn, that doesn't sound promising.
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AndyH-ha
post May 4 2008, 22:48
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I donít know about Audition 3, I still use CoolEdit200. The Help under Convert Sample Type here is quite clear. It says that quality settings of 100 to 400 give the best results. Higher quality settings can cause high frequency ringing because of the steep filters employed. Since this recording has so much energy above 22050Hz, it may be a good candidate for such problems.???

In the old Syntrillium forum, the word from the developer was to use 250 for the quality setting. Calculation times are greater at larger settings but perceived quality will not improve above 250.

QUOTE
C (96 > 44.1 > 96) could be subtracted from the original struck triangle sample and leave no audible difference signal.
What does this mean? If you compared the original with a resampled to 44.1 back to 96, there would have to be a major difference since nothing above 22050Hz could be in the resampled to 96kHz Do you simply mean you could not hear anything from the difference file?
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MLXXX
post May 5 2008, 02:14
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QUOTE (AndyH-ha @ May 5 2008, 07:48) *
I donít know about Audition 3, I still use CoolEdit200. The Help under Convert Sample Type here is quite clear. It says that quality settings of 100 to 400 give the best results. Higher quality settings can cause high frequency ringing because of the steep filters employed. Since this recording has so much energy above 22050Hz, it may be a good candidate for such problems.???

In the old Syntrillium forum, the word from the developer was to use 250 for the quality setting. Calculation times are greater at larger settings but perceived quality will not improve above 250.

I did not read the help, but simply selected the maximum quality, assuming it would give the best result. There was also an option not to use any filtering at all but that didn't seem a good idea so I left filtering on. In light of this, I guess I'd better read up on what the r8brain help has to say about the quality setting.

QUOTE (AndyH-ha @ May 5 2008, 07:48) *
QUOTE
C (96 > 44.1 > 96) could be subtracted from the original struck triangle sample and leave no audible difference signal.
What does this mean? If you compared the original with a resampled to 44.1 back to 96, there would have to be a major difference since nothing above 22050Hz could be in the resampled to 96kHz Do you simply mean you could not hear anything from the difference file?
Yes, simply that. During playback the volume bars on cooledit showed a burst of signal at the beginning of the difference file, but I could not hear that burst (using the same gain setting as for listening to the unaltered sample). As you suggest, there would have been high frequency content in the 22050 and above range.

I find this technique of listening to a difference file quite useful for pinpointing weaknesses (or anomalies) in digital signal processing. It enabled me to establish that Audition 3 at its maximum quality setting was fractionally altering the overall level of frequencies well down into the human audible range, when perfoming a 96KHz to 44.1KHz and then back to 96KHz conversion.

*************

I suspect that this matter of what filtering to use may ultimately prevent coming to an agreement on the resampling question in relation to 44.1KHz vs 48KHz. Any attempt to present a case that the 44.1KHz version sounds different can be dismissed by reference to filtering effects. The Nyquist limit being relatively close to the upper limit of human hearing, no doubt makes filter design difficult.

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krabapple
post May 5 2008, 03:30
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Again, perhaps you could post some lossless samples of

1) the original audio

2) the audio after your processing

'
With #1, other people could attempt to replicate what you did (resampling)...with 1 and 2 they could replicate the listening test you did and measure what, if anything, is different.
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digital
post May 5 2008, 05:05
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MLXXX

It'd go a long way if you could please post your ABX results.

Andrew D.
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MLXXX
post May 5 2008, 05:44
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Yes I can and will do that, digital, though at this stage my main interest is receiving suggestions as to what software to use for the sample rate conversions.

I could merely upload the r8brain high quality conversions (which I have informally ABX tested and found to be distinguishable), but if someone can suggest software that will have less effect on the human audible tonality for a 44.1KHz sample rate than r8brain, then I am ... er ... all ears.

One suggestion (AndyH) was a lower quality conversion setting for Cooledit, and I guess I could try that with Audition 3, or with my expired trial version of Cooledit.
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KikeG
post May 5 2008, 08:45
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I wouldn't trust much signal substraction techniques here, because the filtering may introduce small delays in the processed signals. This delays will leave a small residue when doing the substraction, no matter how good the resampling.

To check if there is such an issue, with Audition/CoolEdit Pro take a spectral look at the difference signal with the FFT view or whatever it was called. If it has significant content (say over -120 dB) only at the ultrasonic part, then both the resampling is ok and hasn't caused any delay either.

AFAIK Audition/CoolEdit Pro resampling is very good, but make sure you have the pre/post filtering option enabled. 400 quality will make a very sharp filter, leading to a possible long ringing at half the sampling frequency (22050 Hz) if the signal has content at this exact frequency. As said, try with 250 to see if this makes a difference.

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MLXXX
post May 5 2008, 18:25
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Inconclusive investigations at a target rate of 44.1Khz:

Quality settings

The wording of the Cooledit 2.00 help on conversion quality includes the following:

Low/High Quality
Use this slider to adjust the quality of the sampling conversion.
Higher values retain more high frequencies while still preventing aliasing of higher frequencies to lower ones, but the conversion process takes longer. A lower quality setting requires less processing time, but results in certain high frequencies being 'rolled off', leading to muffled sounding audio.

I decided to give Cooledit another trial (on an old pc on which it had not previously been trialled). I found that reducing the setting from 999 to 800, 600, 400, 250 and down to 150, merely softened the clarity of the sound more and more, but did not improve it.

The behaviour was similar with r8brain - it sounded best (to my ears) at the highest quality setting. Similarly with Audition 3.0.

Subtracting converted files from each other

Cooledit produced odd results in that it was not internally consistent up to midrange frequencies. A low quality conversion subtracted from a high quality conversion did not merely yield whispers of very high frequencies but a whole swathe of sound well down into audible frequencies.

Both r8brain and Audition 3.0 produced the same level of audio output up to midrange frequencies. Subtractions between r8brain and audition 3 yielded only very high frequency audible sounds, and the sound was faint. I was inclined to reject Cooledit, based on its internal inconsistency.

No proven converter available

My difficulty in proceeding further with this exercise is that the highest quality level conversions of r8brain and Audition 3.0 are yielding slightly different sounds, and they both differ from Cooledit.*

In these circumstances, I cannot draw any definitive conclusion from any positive ABX result when comparing the 96KHz version of the struck triangle to a 44.1KHz conversion using any of these three items of software.

Any difference I heard could be explained away by reference to the filter characteristics used for the conversion.

The only tentative conclusion I can draw is that 44.1KHz may be too low a sampling rate for practical filters. If that is so, then a higher sampling rate may be called for.

I would mention that to my ears there is a greater apparent difference between the original sound sample and any of the conversions (listened to with foobar, an Audigy 4 card, and headphones) compared with differences between the conversions. All of the conversions sound a little duller than the original.

However there could be a large number of reasons why a sound card might perform differently with a 96KHz input than with a 44.1KHz input, including its own filter settings.

As for the differences in sound resulting from use of the three forms of conversion software, I have to assume the filter implementation is different in each case, and this is giving a slightly different colour to the processed sound.

______________________

* ABX report for two of the converters, r8brain 1.9 and Cooledit 2.0, operating at their highest quality settings and converting a 96Khz/24 bit file to 44.1Khz/24 bits:-

foo_abx 1.3.1 report
foobar2000 v0.9.5.1
2008/05/06 04:02:33

File A: C:\Documents and Settings\All Users\Documents\triangle-2_2496_r8brain-conversionTo44-1--HighestQuality.wav
File B: C:\Documents and Settings\All Users\Documents\triangle-2_2496--Cooledit--ConversionTo44-1--quality999.wav

04:02:33 : Test started.
04:02:54 : 01/01 50.0%
04:03:48 : 02/02 25.0%
04:04:53 : 03/03 12.5%
04:05:28 : 04/04 6.3%
04:06:41 : 05/05 3.1%
04:06:43 : Test finished.

----------
Total: 5/5 (3.1%)


And now a similar ABX report comparing the conversions of Cooledit 2.0 and Audition 3.0 with each other:-
(Note: these two sounded quite similar and were not easy to ABX!)
foo_abx 1.3.1 report
foobar2000 v0.9.5.1
2008/05/06 19:48:04

File A: \\action\shareddocs\triangle-2_2496--Audition3convertingTo44-1KHz-quality999.wav
File B: \\action\shareddocs\triangle-2_2496--Cooledit--ConversionTo44-1--quality999.wav

19:48:04 : Test started.
19:48:55 : 01/01 50.0%
19:49:53 : 02/02 25.0%
19:51:59 : 03/03 12.5%
19:52:39 : 04/04 6.3%
19:53:00 : 05/05 3.1%
19:53:23 : Test finished.

----------
Total: 5/5 (3.1%)

LINKS TO THE THREE CONVERSIONS:
Audition 3.0 version: http://www.hydrogenaudio.org/forums/index....ost&id=4441
Cooledit pro 2.0 version: http://www.hydrogenaudio.org/forums/index....ost&id=4442
R8brain 1.9 version: http://www.hydrogenaudio.org/forums/index....ost&id=4444


LINK TO THE ORIGINAL SOUND SAMPLE:
The original 96KHz/24-bit sample of a triangle being struck can be located on the excellent PCABX test page: http://64.41.69.21/technical/sample_rates/index.htm
The relevant sample is the one marked "Triangle Reference Presented At 24/96".

This post has been edited by MLXXX: May 6 2008, 12:55
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2tec
post May 6 2008, 07:55
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QUOTE (krabapple @ May 3 2008, 18:38) *
No, I think you're just not reading carefully, or not understanding the concepts involved. I don't see anyone else here claiming to be confused by the two statements.

Sure, go ahead, think whatever you like. I see that you sure like telling us what that is! As for anyone else, why would they want to get involved in your argument? Personally, I simply don't understand what you hope to gain by insulting people. However, if you feel it helps your cause, please, don't stop simply on my account.
QUOTE (krabapple @ May 3 2008, 18:38) *
And you're still wondering, even though, 'as everyone else knows', you were informed days ago that there were no scores 'above average' (at the p<.05 level)?

As I said, I "was" wondering. Perhaps you should try reading my post more carefully?
QUOTE (krabapple @ May 3 2008, 18:38) *
Btw, your statements seem confused.

There you go with the insults, again. Good luck with that!
QUOTE (krabapple @ May 3 2008, 18:38) *
Are you saying you're NOT suggesting that that a proper re-test of a putative high scorer on a DSD vs Redbook test, would be to see if they could tell 16-bit from 24-bit audio?

Why don't you quote me?
QUOTE (krabapple @ May 3 2008, 18:38) *
You don't seem to have exploited the help you've already been given.

I'm doing just fine, thanks. cool.gif By the way, I feel I must compliment you on how well you've chosen your nickname. I found it amazingly appropriate.

This post has been edited by 2tec: May 6 2008, 08:04


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Censorship reflects society's lack of confidence~Potter Stewart
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2tec
post May 6 2008, 08:28
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QUOTE (Pio2001 @ May 1 2008, 07:40) *
Thus retesting was not needed. Which answers 2tec original question : both average results and individual results were taken into account. There was no positive result.
Thanks! smile.gif
QUOTE (Pio2001 @ May 1 2008, 07:40) *
In the Detmold university listening test, 200 listeners took the same challenge. Some scored above the significance threshold, but this was coherent with random guessing at the collective level. However, one of them got a score of 20/20, which is significant even in a collective test with 200 listeners. The authors said that unfortunately, a small noise at the beginning of one of the samples, though unheard by the listeners, may have biased the result.
Maybe also this listener really hears ultrasounds... I don't remember the study talking about his or her hearing ability in high frequencies.
Hopefully, I'm not just beating on a dead horse here, however, I do have several more questions, please? First off, could conducting audio tests at higher than normal listening levels, reveal subtle differences being missed by current ABX testing? Secondly, doesn't the one 20/20 score in the Detmold study, merit further investigation into exceptional cases of hearing ability? Third, is there any possibility that the test equipment was simply unable to reproduce the difference?

Furthermore, I feel I must apologize in advance if these questions seem too repetitive or rudimentary for some people here.

This post has been edited by 2tec: May 6 2008, 08:32


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AndyH-ha
post May 6 2008, 10:19
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If there is one person way outside the range encompassing everyone else, even if that one personís score is completely valid, we have to ask if the fact has any relevance. Suppose one person in a million can really detect a difference, but the other 999999 can not? If you happen to be interested in the abnormal, then you may want to located these (relatively) few individuals so you can subject them to laboratory degradation, but if you are interested in just about any other aspect of audio, you probably could not care less about them.; they just are not relevant.

There is a possibly important aspect of the test equipment in such comparisons. Many, possibly most, soundcards have somewhat different performances at different sampling rates. If no one detects any difference in the audio, the soundcard differences probably donít matter, but if there are positive scores, we have too many variables to eadily determine why. at the very least we need to repeat the tests with different, high quality, DACs.

With higher sound pressure levels, more intrinsic audio differences will be audible. This isnít specific to different sampling rates, it is a normal part of every day sound. Suppose something is audible (only) at very high levels. The basic question of paragraph 1 applies. Do we care? Why do we care? Will the fact ever be relevant at any time other than during such a test?

The equipment again comes into consideration. It is possible to build enormously powerful amplifiers, but the transducers for converting that electrical power into sound are another matter. Speakers without a lot of distortion get to be very expensive. I think it is probably not possible to brush aside the strong possibility that because of complex interactions in the transducers, higher frequency distortions might have effects on audible frequencies that would not occur otherwise.
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