YOU ARE NOT DOING THIS CORRECTLY. THERE SHOULD BE A STEADY TONE (NOT MODULATED IN AMPLLITUDE) WHEN LISENING TO ONE CHANNEL ONLY THROUGH HEAPHONES. YOU ARE MODULATING BOTH CHANNELS IN AMPLITUDE WHICH IS A TOTALLY DIFFERNT EFFECT AND MODALITY.
I can tell you really care about this, which is great ... but there's no need for accusations. What I uploaded to YouTube was a video with two pure sine waves, with the exact frequencies transparently displayed on the screen. Nothing else. I'd be interested to know what you're using to inspect the audio channels, so I can reproduce your results on my end.
Mike Petroff