https://soundcloud.com/thiocyclist/tone-knob-sweep-song-2
What you hear first is me sweeping the knob, then I do a couple versions of Song 2 on either side of the sweep. Recorded in one take, no effects, no nothing. If you can't hear it you're deaf!
Funny that. The second part of your Song 2 actually sounds quieter than the first part when I listen to it this end, whereas the soundwave on the track looks obviously like it peaks higher on the second part.
It could be that the true deciding factor here (ie whether one believes your theory or not) is that it depends how each individual listener's hearing works/how they hear different frequencies.