This is a touchy subject but this is the place.
What seems lost in that article is the “other side” of the argument and cite tests where people concluded various types of equipment sounded the same as proof the test doesn’t work.
It only means in those tests, there was no conclusive result. I have participated in a rigorous ABX test and could hear and identify some differences between amplifiers bfd.
The other side is the high degree ones sense are all tied together and based on what you already know. I know this sounds hard to accept but recent discoveries on our senses are shedding more and more light on the subject of this interconnectedness and prior knowledge.
A cool show was on the science channel the other night "to see or not to see" which dealt with the senses.
An example is below, think your ears and senses are infallible, that your ears are not affected by what you see and expect?, try this test and see.
http://www.wimp.com/mcgurkeffect/
The usefulness of this and lets call it “testing without prior knowledge” is that it removes what you know about the object under test.
There are examples of testing without prior knowledge all around us.
For example, when you do a vision test, you try to read smaller and smaller letters.
Notice WORDS are NOT used even though you read words, the reason is they want to remove any “prior knowledge” and if you used words, peoples vision (because of the ability to guess the letters) is greatly improved compared to random letters which depends entirely on making out each letter individually reflecting only ones visual acuity.
In a hearing test, one sits and signals when you hear the sound. There is no red light that goes on, there is no visual contact with the person running the test, there are no clues to the presence or absence of the test tone, you must depend only what your ears alone can tell you. If there was a visual signal too, like a red light coming on each time, like the tester winking at you, the test results are much better, better because they included more than just your hearing alone.
In commercial sound, there is a similar test, intelligibility. A series of random words (usually 200) are used, the score depends on how many words you could make out correctly. Here It doesn’t matter how “realistic” or natural sounding the words are if you can’t hear what word it is. Here it doesn’t matter what you know about the speaker or what you can see, only what you can hear governs the ineligibility.
Interestingly, unlike intelligibility, one could argue that since one has no idea what the original performance sounded like from the mic positions, or how the recording was mastered and shaped into stereo, that this is sort of a vision test where both you and the doctor have no idea what’s on the test card. It is a judgment based entirely on your knowledge and expectation of what it should sound like. In the extreme case of subjective error, a very natural voice sounding reverberant field conveys no intelligible information.
With the McGurke effect, one hears the sound correctly when one’s eyes are closed but when the eyes are open, you hear only what corresponds to what you see.
While the scientific rigor needed to do medical or other full out scientific testing is high, the usefulness of it can be realized at a much simpler level.
For the curious, what you need is a way to quickly / instantly switch between A and B and not know which was which.
One does the test when you feel like it, not under pressure or hurried. You do it on your own equipment in your own room at your leisure.
I found that searching through recordings to find passages that “brought out” differences and then using these when switching back and forth was most useful.
In auditioning amplifiers for example, it was interesting that the formerly large audible differences some “heard” going into it, were often greatly reduced greatly when the amp in question was “unknown” and did not return when switching back to the known condition and this was emotionally distressing for some.
For that reason, I wouldn’t suggest doing these kinds of tests in the home unless one is prepared to possibly lose some of the ”magic” part. But if you’re doing product engineering and want to hear the actual differences limited to the sound reaching your ears, then this can be useful weeding out differences especially when it involves a great deal of money (like which crossover parts to use).
If you really can’t hear the difference between A and B, even with the most revealing recordings, how valuable is this change?
If you could clearly hear a big difference before the test but smaller or not at all after, what does that tell you about what you were hearing before?
If you can still hear a difference without prior knowledge, was there any harm or risk in simply trying the test?
Sure one can do the test incorrectly or in a biased way or argue that the end user doesn’t need to or even shouldn’t separate these things, but this doesn’t change the fact that when they test just one of your senses, this IS how it’s done.
When an audio evaluation is limited to just the vibrating airborne sound entering ones ears you also get more accurate results when you eliminate the other non-acoustic inputs.
Best,
Tom Danley
Danley Sound Labs