High frequency capacity can diminish with age, and does.
What does not go away and allows 70 year olds to evaluate tweeters..is... temporal acuity.
Our hearing is based not on frequency range but on complex temporal harmonic transient (macro and micro) timing position, level, and interleaving. Frequency extension is only part of the story.
Electronics and measurement hardware discern all of that (all of what the ear does) via frequency extension capacity -only.
The ear does not do it that way.
eg, a tube amp that cannot go above 20khz or even 15khz, without a reduction in level..,it can still do a two channel timing interval difference of an easy 1mhz. or...one millionth of a second of difference. Ie, a transient can be pulsed through one channel and then pulsed through the other and be timed at one millionth of a second part.
ie, a LP or record, can do -approximately- (properly set up, at it’s limits) a 7 millionth of a second interval in inter channel timing (of signal). This is why a record can outclass 192khz audio, as it does things that are important to how humans hear. Digital is very poor in the area that is important to the ear. The seven millionth of a second number, is the approximate physical limit of the mechanics of an LP and stylus combination. (then all the work that came before the record was made real, all those ducks have to be lined up as perfect as possible, in order to really bring this point to life--in the given LP record)
For the ear, that is the important part. Frequency extension means almost nothing.
The ear can do complex harmonic interleaved signal discernment to the tune of many hundreds of kilohertz (hundreds of thousandths of second), in each ear. It can then combine that between the ears,and individually in each ear.
Ergo...it is very sensitive to jitter, as that is almost....the whole art of hearing itself. This part never leaves the ear, it remains even when frequency extension of the ear diminishes radically. The capacity to hear multiple levels and interleavings of 100khz and +200khz complex harmonic structures together, with zero jitter issues - is always there.Then the mind/biology connected to the individual ear, how good are those individual packages - and as a set?
Yes, an 80 year old man, a learned and lore filled audiophile version of that 80 year old man... with diminished high frequency hearing... via listening...can accurately tell you which digital cable has the lesser level of picoseconds of differential in production and navigation of jitter. FACT.
This is how an older man of 80 with hearing loss and a loss measured to be a serious drop at over lets say, 5khz, can still tell the differences between a good or a bad tweeter design.
Again, frequency extension of electronics or measurement means almost nothing....as the ear does not work that way. The ear is not a piece of human engineering of hardware. It is a totally different acting and operating piece of incredibly complex biology.
One can measure but one has to measure and compare what is important. So far, electronic measurement and human hearing as a coupled system of relation (to attempt scientific discernment for the purpose of application of engineering), is almost missing the whole boat.
Various people, at times, over the decades... have tried to explain this to the audiophile masses but the people have to ’get it’ as well, for it to sink in and become a very much needed norm. We’re getting there, but it is slow rowing out here in the desert...
This is the start of the necessary point of discernment in figuring this out. It gets more complex than that, but this is most definitely a doorway to that discernment. The map is not the territory but first one has to at least draw a map that is connected to the territory. Otherwise you’ll get this circular argument that has been here for decades.
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To me, none of this means anything if you are not having a good time listening to music.
