Some years ago Rick Campbell wrote an excellent article for QST describing a 'Binaural Receiver' http://www.arrl.org/files/file/History/History%20of%20QST%20Volume%201%20-%20Technology/QS03-99-Campbell.pdf.

The basic concept is that you use a quadrature mixer for the final IF converter, and the two outputs are fed to left and right headphone channels.

It just struck me that a cheap and dirty version of this should be attained using our Hi-Per-Mite CW filters.  If you have one set up for 700 Hz, and another one for 770, or 640Hz center frequency, each feeding the left or right headphone channel, much the same effect is achieved.  The different phase shift that each filter has for each frequency will give a sensation of depth, helping the ear pick out signals in a crowded band.  I haven't verified this yet, but I will as soon as I get some workshop time.

73 Dave NM0S