opaqueice;352675 Wrote: > No, that's exactly what I said (several times already). The > questionnaire/listener response part of this study was more or less > identical - other than the length of the samples - to those previous > papers. Its results contradict those of the previous studies.
Ah, you're talking about just the 3rd (minor) part of this test, the subjective evaluation part. I really missed that and you could have guessed because I was writing about the EEG and PET all the time. Indeed, they used a similar questionnaire and found a difference using longer samples and intervals than the other ones. But that is just part 3 of this test and you conveniently leave out the other 2 major parts so you can say the whole study is similar to previous ones? That would not be correct. But you also missed a very important part of that subjective testing, I quoted it before but you probably misread it as being the part you had in mind. So let's see what happened in this part 3 of the test. They had found an average 10's of seconds "delay" between starting the full-spectrum sound and the brain reacting. Same for stopping the sound or just cutting a component of it: the brain still went on in it's more-active state for an average 10's of seconds. These findings lead to this: "It seems, therefore, that an exposure to FRS shorter than 20 s, as recommended by the CCIR and ITU-R, may be insufficient to introduce a physiological effect. By the same token, a short exposure to HCS following FRS with a short interval of 0.5-1 s may not be enough to withdraw physiological effects, if any, induced by the preceding FRS. Based on this physiological consideration, we performed our psychological experiment with sound materials of longer duration. " And here we are: the subjects now hit the right targets in a subjective test too, like you say, contradicting previous tests that used the CCIR/ITU method of short samples and intervals. And now comes the part that you missed: They did another subjective test and I quote: "We also examined the psychological evaluation using the same material and sound presentation system as was used for the present study, but followed the presentation method recommended by the CCIR, and confirmed that the results were in agreement with the studies by Muraoka et al. (1978) and Plenge et al. (1979)." And what do we have now? When they use short samples and intervals like in all those previous tests, we get the same results as they did in those previous tests!!!!! And don't forget: they used double blind testing here! So --that-- is the reason I was saying that the results were -not- in disagreement with the previous tests. They repeated using the same procedure of those tests and got the same results as those tests. Only when they changed the test with the longer samples and intervals, they get different results. They confirmed that this was a result of the changed durations of samples and intervals. > That was for the EEG part of the experiment. As far as I can see they > never describe the conditions under which the questionairre part was > conducted. True, but when they make a big point of subject comfort on both EEG and PET testing, one can assume they did the same for the subjective part. It would not be logical to assume that they would radically change this. They went to great pains to check on comfort, even performing EEG scans while the subjects went into the "scary" PET scanner and eliminating the results of one subject whose EEG clearly showed he/she wasn't in love with the PET scanner or radio-active injection ;-) Also, we can assume that they did all subjective tests in the same room with the same conditions in which case they would not have been able to demonstrate the different outcome with short samples and intervals if what you say would be true so they eliminated that possibility by doing both subjective tests. > All natural sounds have harmonics. Precisely how much is present will > be a function of the specific environment. But just as an example, an > NTSC TV screen produces a sound around 16kHz (which I can hear, by the > way) plus harmonics. Computer monitors also produce HF sounds, as do > florescent lights, and probably lots of other household electronics. >From what I read in this forum, we all are blessed with an above average hearing because we could all hear the 18 kHz sample in that on-line test! But just to make sure: sounds from TV's, monitors, lights etc. are not natural sounds, they are all man-made. Also, most of these are of a stationary nature, like the 16 kHz NTSC we hear (PAL gives less discomfort btw). Also, the amplitude of these sounds are well below the dB level of the HF components of music used in the tests. The graph shows that the average dB level (avg for duration of the song) for say 20 kHz was -20 dB from the full-spectrum (which was played at 80 dB) which will be way louder than the emissions from TV's etc. But for all we know, a random sweep-generator operating between 20 and 100 kHz with power amp and HF tweeter might give us the same improved experience! It would however be a big annoyance for our cats and dogs so I would choose hi-res music even if someone proves that the sweep-generator is just as effective! > There is no evidence for that assertion. Time and time again > audiophiles have made such claims, only to fail completely when asked > to distinguish blind. The study we're discussing used double blind method and tested both the established CCIR/ITU protocol like the tests you refer to plus, the new protocol with longer samples and intervals. The difference was demonstrated plus the underlying mechanism that is responsible for this difference, and I see no objective reason to question these results. I mean, you can repeat CCIR another 1000 times and "prove" 1000 times that the subjects can't tell the difference but that is of no use when it is demonstrated that the method is unable to show the difference. It would be much smarter to repeat the test with the long samples and intervals because no-one yet discovered an objection to this method, although I'm sure someone will soon after reading this (like you don't remember after 10 second interval between samples blah blah and all invalid because remember it's double blind so random selection would be the result, not positive hits). I read stories about dis-illusioned audiophiles that sell their high end kit after failing a test because they are now convinced they imagined it all... only to find after some time that they don't enjoy the listening experience anymore and they buy good kit again and the joy returns. Or I can refer to the study done by Neve with professional subjects that finds that the HF component matters a lot: "Nevertheless, and interestingly enough, artists and engineers working to produce acoustically perfect music for commercial purposes are convinced that the intentional manipulation of HFC above the audible range can positively affect the perception of sound quality (Neve 1992)" So how many times will we bounce the ball back? I'll only be open for new tests that use the new procedure and will discard all CCIR/ITU based tests as flawed silently. > I'm simply applying precisely the same convoluted logic to the > instruments the experimenters applied to human hearing. I know you're doing that, but is it relevant? Do you think that a PET scanner that detects radio-activity gives false readings when music with HF components is played in the same room while scanning? Do you think equipment like that would be approved for use in hospitals where HF is present from so many machines? When you do believe the PET scanner is suspect, you would indeed discard any results obtained from it, incl. all patient related scans. But if you believe that the PET scanner works, why make a point of it here? I mean, if you doubt technology at professional medical levels, why bother with consumer technology at all? > What world are you living in? In mine, hi-res audio formats are dead > (albeit still twitching occasionally). I think you are referring to SACD or DVD-audio? But do you realize that a webshop with 24/48 or 24/96 flacs is a hi-res format too? I don't defend any specific format, I want hi-res in whatever form! BTW, amazon lists many new releases for both formats and even pre-orders for upcoming ones even for 2009 releases. Also, new players are still released so I don't think it's dead. It is like the transporter: a high-end niche. But we, audiophiles, are what makes that niche and not some clueless RIAA sales statistics that are for the dumb masses with their iPods. They even count hybrid SACD as regular CD, how daft can you be? So, in your world, is it bad news for people like Sean with hi-end audio kit like the transporter, or just bye bye to SACD/DVD-audio? I hope your world has a place for improvement because red book is definitely not the best we can do now and certainly not the best for the future. Some recording studio's are already using 32/192 so that their 24/96 "masters" are without artifacts! cheers, Nick. -- DeVerm ------------------------------------------------------------------------ DeVerm's Profile: http://forums.slimdevices.com/member.php?userid=18104 View this thread: http://forums.slimdevices.com/showthread.php?t=54077 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
