In any case, I will just go with what works, knowing that a null test will not give me any useful information.
As far as I'm aware, your auditory system is left intact when you just can't see the box of gain. 😀
Well, I've participated in auditory DBTs and frankly, I don't remember the part where my eardrums were punctured or I was forced to listen to techno. I just listened to music, diddled the volume control, and switched back and forth at my leisure. Then I made a choice and went on with my life. 😀
Sy,
First, the blind tests I've read about don't use equipment or sounds systems the person is familiar with. Also, you change the conditions and you change how you respond a sound. The tests I read about, do not give a person experience or practice with blind testing, which is a new experience. Habituation takes time.
First, the blind tests I've read about don't use equipment or sounds systems the person is familiar with. Also, you change the conditions and you change how you respond a sound. The tests I read about, do not give a person experience or practice with blind testing, which is a new experience. Habituation takes time.
You need to do more reading. 😀
FWIW, the last two tests I participated in as a subject, one was with my own system, the other was with a digital source and top-of-the-line Stax headphones. I wasn't super-familiar with that latter setup, but was quite content that what I was hearing, I was hearing. Several more were described in detail in my Linear Audio article.
Harman has their listening panelists undergo extensive training, and it makes a huge difference in the repeatability of the results. The listeners are also tested for standard hearing acuity. Interestingly, professional audio reviewers often have abnormal hearing, i.e., deficiencies, and the scatter in their results is often quite high --- but they also usually forgo the training.
Perhaps it's out of fear of the electric shocks if they don't pick the Harman products.
That was a joke btw.
So in the end it is sufficient to be quite content with ....... (SCR)
I´m sorry but that is a contradictio in ratio; if it would matter what participants _think_ about their ability we would not need to do any controlled listening test at all.
If a test has a positive result (aka null hypothesis could be rejected) but no negative control was used, nobody knows if the result was given due to an audible difference
If a test has a negative result (aka null hypothesis could not be rejected) it does not help that the listener was content about his hearing, nobody knows if the result was given due to the fact that he could not hear a difference under test conditions.
BTW, Sy what about the suspension of high standards in the Fremer case?
Any arguments?
I´m sorry but that is a contradictio in ratio; if it would matter what participants _think_ about their ability we would not need to do any controlled listening test at all.
If a test has a positive result (aka null hypothesis could be rejected) but no negative control was used, nobody knows if the result was given due to an audible difference
If a test has a negative result (aka null hypothesis could not be rejected) it does not help that the listener was content about his hearing, nobody knows if the result was given due to the fact that he could not hear a difference under test conditions.
BTW, Sy what about the suspension of high standards in the Fremer case?
Any arguments?
Since we beat the Fremer deal to death months ago, why do you want to beat it around more? Is it total ignorance of statistics? Or an insistence on accepting post hoc reframing when it suits your desires? Or a desire to accept poorly controlled results when that suits your desires?
People can either hear these things with ears-only or they can't. No-one claiming "magic" differences has offered up any reliable evidence. Period. Trying to kick up unrelated dust to confuse the issue doesn't change it, nor does constant moving of the goal posts.
People can either hear these things with ears-only or they can't. No-one claiming "magic" differences has offered up any reliable evidence. Period. Trying to kick up unrelated dust to confuse the issue doesn't change it, nor does constant moving of the goal posts.
Some DBT get in the way.
Unless any give test show that it can produce also positive results, that test is meaningless and invalid.
The assumption that because of a test is blind it eliminates anything that may interfere with pure auditory perception – that assumption isn't based, and at least in some cases I know of, is erroneous.
Hello John, you mentioned many times that (Carver) null test doesn't provide any useful information. Meanwhile you and Walter Jung (TAA 4/85) had used null test for capacitor quality measurements. Does this mean that capacitor measurements weren't done in the proper way?
But it does, as has been pointed out and linked about a million times. So instead of criticizing blindly (as it were), why not actually read some research papers?
A lot of room for doubt --->
1. I was sent a mic preamp that a record producer said had noise in it.... could I fix it. I listened with headphones and didnt hear anything unusual. After a 1/2 hour phone call describing the quality and nature of the sound I was to hear and asking me to listen "deeper" after several attempts.... i finally did hear it. A low freq steady tone. (probably a ac line harmonic). Afterwards i heard it easily and always when I put on the headphones. It was subtle but it was there. Surely would not be heard in a dbt between mic preamps. It helps to listen Hard and long. But it helped me when I knew what I was expected to hear by another who had heard it.
2. Swedish Radio developed an elaborate listening methodology called "double-blind, triple stimulus, hidden reference". 60 "expert" listeners spanning 2 years and 20,000 evaluations finally concluded which codec was transparent and could be used.
A sample of the codec was sent to the late Bart Locantli - an acknowledged expert in digital audio and chairman of an ad hoc committee formed to independantly evaluate low bit-rate codecs. Locantli instantly identified an artifact of the codec. After Locantli informed the S.Radio of the artifact listeners at S.Radio also instantly heard the distortion.
Locantli used observational-listening technique which audiophiles routinely use. (this story is doc in AES pub).
I think it could be that Locantli knew what to listen for in artifacts of codecs before he startd to listen. Something he had heard before or learned from theory even (?)
F.Toole has shown in narrow tests for specific things what audiophiles have said for years- they can heard much lower than 1 db changes. they can hear much less than 1% thd. etc. Scientific tests do show positives.
There is plenty of room to doubt the results of many dbx test as the total answere for all time. Even on a scientific testing basis. -Thx RNm
1. I was sent a mic preamp that a record producer said had noise in it.... could I fix it. I listened with headphones and didnt hear anything unusual. After a 1/2 hour phone call describing the quality and nature of the sound I was to hear and asking me to listen "deeper" after several attempts.... i finally did hear it. A low freq steady tone. (probably a ac line harmonic). Afterwards i heard it easily and always when I put on the headphones. It was subtle but it was there. Surely would not be heard in a dbt between mic preamps. It helps to listen Hard and long. But it helped me when I knew what I was expected to hear by another who had heard it.
2. Swedish Radio developed an elaborate listening methodology called "double-blind, triple stimulus, hidden reference". 60 "expert" listeners spanning 2 years and 20,000 evaluations finally concluded which codec was transparent and could be used.
A sample of the codec was sent to the late Bart Locantli - an acknowledged expert in digital audio and chairman of an ad hoc committee formed to independantly evaluate low bit-rate codecs. Locantli instantly identified an artifact of the codec. After Locantli informed the S.Radio of the artifact listeners at S.Radio also instantly heard the distortion.
Locantli used observational-listening technique which audiophiles routinely use. (this story is doc in AES pub).
I think it could be that Locantli knew what to listen for in artifacts of codecs before he startd to listen. Something he had heard before or learned from theory even (?)
F.Toole has shown in narrow tests for specific things what audiophiles have said for years- they can heard much lower than 1 db changes. they can hear much less than 1% thd. etc. Scientific tests do show positives.
There is plenty of room to doubt the results of many dbx test as the total answere for all time. Even on a scientific testing basis. -Thx RNm
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I just don't read the 'right' research papers. I read papers on how to IMPROVE audio design, rather than to negate it.
Dimitri, I would think that a cap subtraction test WITH a measurable and significantly different residual, depending on most cap types, is DIFFERENT from an A , B or X test. Time itself seems to be used in a different way.
An amplifier subtraction test might be OK, but it would seem that much of the residual might be just artifacts of out of band phase and amplitude shift.
An amplifier subtraction test might be OK, but it would seem that much of the residual might be just artifacts of out of band phase and amplitude shift.
And a lot of what really counts in achieving realistic sound is about this type of distortion, as in eliminating it. The simplistic DBT won't pick it, but if you're subjected to the adverse component being there continually, sooner or later it will be a glaring artifact, that will irritate until you get rid of it. Once you're aware, the mind rushes to check whether that element is still present when you switch on the system, and there, blast it!!, is the problem still!
These are the sort of anomalies that immediately identify sound as being hifi, rather than the real thing -- you know that the sound is not right, but you would be very hard pressed to precisely describe what gives the game away ... that is, unless you spent many years tracking down these nasties 😀 !
Frank
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