most people don't have golden ears, but some actually do.
I was demo'ing some audio gear (including spkrs) at a show and the spkrs were from someone else. he told me that the red/black posts may not be right. I connected it and used the spkrs anyway.
one guy came by and said he thought the absolute polarity was wrong. I don't believe he was there when the spkr owner explained that to me.
could it have been just a coincidence? maybe. maybe not!
very few people are good 'test gear'. I know I'm not. but a select few really are!
I've run into a couple of cases of "people with golden ears" detecting a fault that the rest of us couldn't hear.
Some years back,I worked at a manned TV/FM Broadcasting Station in the middle of the Western Australian Wheatbelt.
The FM Station's was fed from two discrete Audio outputs of a UHF link,which in turn was fed by a long landline back to Perth.
The Stereo pair of lines were normally equal length.
One of the Techs told us there was something "funny"with the Stereo signal as heard through his home Receiver.
He said it sounded like one channel was out of phase.
We all listened,& couldn't hear anything wrong.
It turned out that the Long Line Techs had found a fault on one leg of the Stereo pair,& not realising it wasn't a Mono line,diverted it to an alternate feed which was around 100km longer,booked the faulty line for repair,& went on their way.
100km is a free space wavelength at 3kHz (probably a bit lower in that particular cable),& various fractions & multiples at other parts of the audio spectrum----definitely enough to stuff things up!
Why we didn't hear it?---Probably noisy environment,less than ideal speaker placement,etc.
The next episode was in a major city TV Station,where one Staff member reported he could hear a "hissing" sound on the TV stereo sound-----again on a home Receiver.
The Transmitters were used "day about",so it was easy to determine which one was responsible,but very difficult to reproduce his results.
We all listened at the Studio,at the Transmitter,& as far as possible,at home.
No sign of a problem!
We looked at the Sound Mod output with a Spectrum Analyser,all looked OK.
The SA was "battling" a bit to see anything that close to the Sound Carriers,but we tried!
No viewers complained,so we told him he had "golden ears" & had much innocent merriment "hissing" at him!
Abruptly,while I was on leave, the "suspect"Sound Modulator failed,with spurii all over the place!
Much egg on many faces!