Quote Originally Posted by jneutron
For a complex musical waveform, if a human is keying on a 2Khz signal, trying to identify the location in space, the rest of the audio signal may be introducing a jitter, or some other phenom similar to it, to aid in lateralization..
Cheers, John
But complex music makes detection vastly more difficult than test tones as it is shifting constantly, not isolated as in test tones. And, you are faced with the masking effects too. So, unless you isolate that 2kHz in a way without the others bothering your attension, It will be most difficult.
That may be the reason why no differtences under bias controlled listeing has been reported so far.

Same principle in detecting JND levels with test tones and music, or distortion.