Re: hmm really
To put it simply, my hearing has fallen off. 15K seems to be my upper limit now. So when I see things like, "to 40KHz", I know that #1 a young human can't hear that high, and #2 the source signal never had that information.
Top quality microphones are rolling off at 20KHz. A Neumann is not a slouch microphone. If the audio information isn't there in the recording, then it definitely shouldn't be there during the reproduction.