Dear Mashif, being a medical specialist in ENT, You are so right! We have a "musical memory". You need to have listened for several years to for example acusic music to learn to rember the special spectrum of frequences that identify each instrument. When you get older and start to loose the upper frequences, your brain only need to hear the caracteristics of a part of the full spectrum of a special instrument to recognise it and fill in the missing frequences. This is natures way of letting us enjoy our music up through our age. Electronic music however can vary in so many ways making it much more difficult to find a special spectrum of freqwuences for the "instrument"to remember.
You also need to deal with these facts when judging the HiFi reviews from eldery experienced HiFi experts. Are they really hearing all frequences or is the brain adding more or less...?