Some years ago, came across an article that took mono audio and
created a false stereo with a low pass filter feeding the left ear, and a
high pass
filter feeding the right ear, which gave the effect of a rising audio
frequency
travelling from left to right, and also apparently aided the reception of CW
because you could "look" in the direction of the signal that you wished to
pick out.

Such an arrangement fits in very well with the headphones generally
available today from Currys and the like.

Also, with computer audio boxes, is ther eany need to actually put
audio amplifiers inside rigs, so just leaving a headphone socket?

I know that I can google for this, but I prefer to foment discussion
in these otherwise-dying NGs in the first instaance, but has anyone
out there got their fingers on the pulse?