Then why do some bad-measuring speakers get glowing listener reviews? Because it is human nature to pre-condition incoming raw sense data (the sound waves) with a suite of unconscious personal cognitive biases, which we are wired to mistake for the raw sense data. That's why some bad speakers still get so much praise. Something non-sonic about them (or their back story) is so well aligned with widespread biases or values that many of us hear their sound as good anyway.
I'm certainly no expert, but I am currently under the impression, based on the reading I've done, that there are some other factors in play. Psychological biases are commonly cited when explaining why measurement and subjective preference don't jive. I think some of the other factors are probably under-examined, such as hearing degradation.
There is a sociological explanation for this. It's called the "fundamental attribution error" or "correspondence bias". The idea is that "individualist" societies' people are biased to explain things by focusing on individual difference (like the placebo effect) while people in "collectivist" societies are biased toward looking to external factors ("environmental" factors). The frequency with which the "few bad apples" fallacy is used to explain/justify/rationalize bad behavior from people in power (and those under their authority) is explained by correspondence bias. If the public is conditioned to think that most things are explained by individual psychology then it's easier to ignore the other factors.
Some possible non-psychological factors:
• differences in the shape of the ear and ear canal. I have heard that wearing earplugs when sleeping could cause a reshaping which could degrade one's hearing quality but I don't know if that's accurate. My father smoked a great deal in the home when I was born and small and I had to have tubes put in due to frequent ear infections. Those are directly linked to exposure to second-hand smoke. I don't know to what degree my hearing response characteristics are influenced by a possible widening. I can say that the tubes were quite painful, probably, at least in part, due to the pressure from their width. I also was "overly" sensitive to loud noises as a kid and thought that that extra sensitivity might be linked to a wider passage for sound to get through.
• differences in the size of the outer ear? (e.g. dinner-plate ears on old men at church)
• presbycusis (according to Wikipedia it can start at around the age of 18). It is the decline of hearing quality due to aging. High frequency loss due to aging has been parodied in pop culture, such as on the lousy comedy 'Thirty Rock' ('Black Light Attack' episode). Although there is some awareness of the issue in general culture (the song 'Buzzin', a harassment device called The Mosquito, and the 'Teen Buzz' ringtone), it doesn't seem to have affected the audiophile world since I've never seen the word presbycusis anywhere (not on audio companies' pages, not in audio forum posts, etc.). Audiologists' tests for hearing apparently don't go into the particularly high frequencies so a lot of people rely on web-based tools. Older people can also have issues with hearing low bass, not just high frequencies.
wiki said:
Age affects high frequencies more than low, and men more than women. One early consequence is that even young adults may lose the ability to hear very high frequency tones above 15 or 16 kHz. Despite this, age-related hearing loss may only become noticeable later in life. The effects of age can be exacerbated by
exposure to environmental noise. Secondary symptoms can include tinnitus and
hyperacusis — heightened sensitivity to certain volumes and frequencies of sound.
• Presbycusis alone is not responsible for hearing degradation in a person. There are the effects of sociocusis (external noise) and nosocusis (health factors, like diabetes and aspirin use) also. A huge portion of people will have their hearing degraded even when young due to things like using portable music players in noisy areas. The WHO estimates that 50% of young adults will develop significant hearing damage from noise exposure. There is other research that shows that even people in the young kid to 19-years-old range will suffer hearing damage (around 15% I think, globally). The rise of "crowd control" devices like the LRAD also is linked to hearing degradation in young people.
• the following, if the image is accurate:
The pervasiveness of physical factors puts more weight on the importance of objective measurements but also casts more doubt on how applicable they are, as individual difference (particularly in terms of hearing damage from living their life — some combination of sociocusis, nosocusis, and presbycusis) is, from my amateur's estimation, mostly very ignored in audiophile circles. I have heard complaints in audio forums about tinnitus and a few comments about not being able to hear past a certain frequency but not much more. I also, though, have only been looking much into the audio world for a short time.
Still, it seems that the overwhelmingly typical thought process is to present the "typical human" in terms of their hearing and how audio devices interact with that. How many of us are typical, particularly given the pervasive influence of sociocusis? If we were in pre-industrial society then the typical human would be much more useful as a model for expected audio experience performance. This is because presbycusis isn't as powerful an influence as sociocusis (and probably also nosocusis — since drugs like NSAIDs and diabetes are both common), on its own. I bet that it happens more rapidly due to the weakening of the auditory system from the influence of sociocusis and nosocusis.
Lead exposure, which wasn't a factor in some pre-industrial societies, is also relevant as it is linked to tinnitus. Lead is not just found in the environment from things like building demolition dust, paint chip dust, and tetraethyl lead fuel additive; it is also present in cocoa. Other pollution factors are ototoxic, too, like styrene. Many things that are dismissed as symptoms of aging are actually symptoms of physical decline from exposure to organic and inorganic pollutants, most of which are the result of industrial activity.
Put simply... different people hear differently, mainly due to noise exposure and also due to age and/or health factors like NSAID use and diabetes. Noise exposure influence seems to be the biggest problem. Not only is it affecting the very young, it not only removes or reduces the ability to hear some frequencies, it also can heighten the awareness toward some. All of this can warp a person's experience of an audio presentation equipment system past the "typical human —
without genetic presbycusis inclination and the influence of sociocusis and nosocusis". If we look at the typical human as being the average, with the effects of sociocusis in particular taken into account then people who have good hearing could be quite disappointed, at least theoretically, with the recommendations.
From my extremely cursory research it seems that the audiology world is focused almost exclusively on the frequency range involving the ability to understand speech. So, it could be that the influence of sociocusis (and/or nosocusis and/or presbycusis) is greatly downplayed by the extant research picture.
All of this suggests that people should have their hearing thoroughly tested and advice models should be able to match what their hearing performance is.
It also suggests that subjectivity-heavy audio reviewers should post the results of a recent hearing test that covers the full frequency range. For more trust in that, the test should be conducted by an uninvolved party. A good number of influential people in audio have silver hair. They may have had golden ears in the past but may not today. Of course, their 20-year-old employee might have worse hearing from a diet of MP3 portable audio and subway commutes. (Research found that NYC subway commuting has a serious degradation effect over time.)
It also suggests that there may need to be multiple models for closer-to-ideal performance equipment matching. This is particularly the case if hyperacusis (and/or notch-dip type loss points within the range a person can hear) plays a significant-enough role. If that's true, though, it may be too difficult to make such a model on anything but an individual level, where a thorough hearing test would model the person's response profile.
At bare minimum, it strikes me as reasonable to assume that people who have lost the ability to hear past a certain frequency don't need to worry about their equipment's ability to produce those frequencies (with the exception of irritating others in the vicinity if the frequencies are quite strongly produced). The situation may be more complex than that, though, such as due to an influence of hyperacusis and/or other distortions (like tinnitus). Tinnitus, for instance, could make concern over things like THD and noise floor less relevant. If one's ears always have a rather significant base level of hiss then it could change the baseline for acceptable equipment noise.
Another thing I've noticed from my subjective experience is that if my hearing is stressed (such as from using the riding lawnmower which, despite the use of both earplugs and headphones at the same time, causes a great deal of stress to my hearing) I notice what is probably upper midrange more, later — after having finished with the mowing and before my hearing has recovered some. It seems that my high frequency hearing is suppressed and the higher frequency range that I can hear is both more prominent and more compressed. It reminds me of things coming more from a telephone speaker than how things sound normally. So, my subjective experience suggests to me that not only can hyperacusis be a potentially very significant issue, there is also the issue of recovery changing a person's hearing quite a bit. All of the reading I've done always seems to downplay the ability of a person's hearing to recover but I know it can. I attended, for instance, one rock concert in my life and it was at an extreme level because (as I found out later) the musicians involved were practically deaf. The opening act was at a comfortable level and then the main act came up. They kept motioning to the sound man to raise the level and my ears rang for a year and a half. I should have left but I drove to Chicago to attend the concert. Although my hearing did recover quite a bit (the ringing stopped) it was also clearly permanently degraded, due to my tendency toward tinnitus which I am certain was greatly increased due to that concert.
If a person's hearing response changes quite a bit, due to noise exposure and subsequent recovery, that also could greatly complicate things when it comes to finding some kind of ideal response to model audio equipment by. I suppose easily-adjustable equalizers are the most practical work-around.