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In Reply to: RE: DBT or not DBT posted by Ozzie on December 02, 2014 at 19:07:52
The problem is…
We have a “learned system”, by that I mean we hear through two inputs and yet our hearing system can take all of the difference between the right and left ear and our brain interprets and makes a single spatial image out of it. That is why two ear spaced microphones do not produce anything like a real stereo image but one measurement mic in mono, 1ch can sound very real.
The system also can ignore a great deal of noise and can fill in the blanks in the famous “cocktail party effect” or listening intently with headphones to a distant signal in the noise on the short wave. It does these things largely without our knowledge or awareness and it is that “automatic part” which is also the real problem.
Worse or maybe just a side effect of a learned system is that actually what our sense of taste and hearing share is that the subjective impression of each are both strongly affected by what you see and know.
For example, nearly always when judging two wines, the one in the fancier bottle is thought to taste better even though it may have originated in the same bottle as the lesser grade.
Our hearing is like that too, it is affected by what we know and expect AND in addition to what we see.
Sounds crazy but it’s true, in fact our sight can completely over ride what we hear (google and watch the mcgurke effect) and what we know can shape what we hear as well.
So, when you have your hearing tested, they limit the stimulus to one domain, your auditor channels, there is no red light that goes on with the tones, if there was one, your hearing would be much better, the person running the test can’t give you any clues, if he winked or you saw him press a button. Your hearing would be much better, even if you weren’t consciously aware of seeing it. So in the hearing test, it all depends on what your ears alone can detect.
Just like with wine coinsures some hifi enthusiasts have an extraordinarily high opinion of their own capabilities and are very proud (and welcome any suggestion along this line, like a country welcomes an asteroid strike).
In scientific testing methodology, for some things blind testing is the norm however. It is the only or at least best way to minimize bias .
To be scientifically rigorous, one must follow all the rules and protocols and use the appropriate math for analysis. To satisfy the nth degree of precision, is far outside of what is done in hifi. In fact, I am not sure people generally understand the connection between what we see, know and expect and what we hear but it is an overriding principal too. We also interpret anything new based on what we already know and understand.
To break the connection between what you know, expect or see and what you actually hear (by hear I mean the air pressure changes entering your ears, all one needs is to arrange a situation where you compare two things without knowing or seeing which was which.
In an informal test like this, do this when you’re comfortable with music you have selected at your leisure and usually with a silent friends help (or use a SBX relay box etc), go back and forth between A and B where you don’t know which is which. When you find musical snippets where you hear differences and then just go back and forth with those snippets.
Often, people find what they had previously heard as a large difference in sighted comparisons becomes a smaller one, once “the knowledge of which one was which” is removed as then your judgment is only based on what reaches your ears.
Do this A VS B comparison as often as you want, whenever you want until you are sure of your conclusion.
I think the reason some don’t like the idea is because that pretty often, once one has heard the big difference disappear, the magic of it usually doesn’t return. The up side for the diy'r is, if you have just made something that does sound better, it is likely to sound better to most everyone else too even when they don’t know what it is.
Hope that helps in a general way
Follow Ups:
You are such a reasoned and reasonable man blowing against the prevailing winds that I salute you.
in determining the *ultimate* capability of a format or a component, you're gonna have to begin with a more capable test rig than did Meyer and Moron.
See "Critical listening position for majority of tests." pic.
No. Amir has passed the modern equivalent of the M&M DBT test using a laptop and a pair of headphones.
The key is training.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
that even Pat would be able to begin to hear differences? :)
That's how to train.
One learns first with severe impairment and then gradually moves to lesser and lesser impairment after symptoms are recognized. This helps in recognizing musical excerpts that are likely to be diagnostic for specific artifacts. This is easily done with dither algorithms by attenuating the hi-res signal, down sampling with the dither algorithm and then boosting back the missing gain. That way one can get any number of bits resolution. One can listen, as I did, to different dither algorithms at the 8 bit level. One can hear distortion (no dither), noise modulation without distortion (RPDF dither), or higher order modulation without noise power modulation or distortion (subtractive dither). Filters are much more complex, but it is possible to learn the effect of different filter parameters (such as those in the iZotope SRC). After a lot of effort one comes to recognize specific impairments fairly easily, given the appropriate recordings. As with bit depth it is necessary to start with higher resolution material, so that the filters you will be introducing will be working on more or less unfiltered music and not the result of filters used in the production process.
It is important to understand that whether one hears something or doesn't depends on many factors, most especially the recordings used, the playback equipment, and the attitude of the listener. If one believes that there is nothing to be heard then one has no chance of ever hearing subtle differences. Of course if one does hear differences, there is the problem of correct causal attribution. However, that's a different problem and requires engineering knowledge and experience with experimental design and logic. Training to hear differences is requires the right tools and lesson plan, but is mostly about concentration, patience and determination.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Sure.
I had very good mentors who began to teach me the subtle aspects of music reproduction starting at age 18. I confess that early on, I could not hear what they spoke of. With practice and exposure to higher resolution gear as compared with live unamplified music (one was on a symphony board and a baritone in the symphony chorus), I began to understand!
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