after reading the other responses, my guess is that there could be something to this if the ear's response is non-linear in some way that makes non-audible freq

after reading the other responses, my guess is that there could be something to this if the ear's response is non-linear in some way that makes non-audible frequencies affect audible ones. that might sound crazy, so let me give an example. cheap active speakers (the kind you plug into a computer) will often pick up radio transmissions from passing emergency vehicles. the speaker cable acts like an antenna and picks up the radio signal. now the radio signal is, of course, at radio frequencies, but there's some non-linearity in the amp that results in an audio signal (an understandable one) coming out of the speaker. that's a fairly extreme example, but here's another more biologically believable one. perhaps there are frequencies which are high enough to be inaudible, but which influence the ear in how it responds to audible frequencies. for example, perhaps the ultra-high frequency signal stimulates the ear in some way that makes it more sensitive to audible higher frequencies. then you would hear a brighter tonal balance when listening live than when listening to a band-limited recording. i am not saying this must happen; i am saying this may be the (physically reasonable) basis for some belief / rumour / knowledge in the audio business. [also, note that the non-linearity must be in the ear; if it's in the surroundings then the mic will pick it up too. and it must be influenced by frequencies that are outside the recording bandwidth otherwise you'd hear it on playback.]