I know your suggestion may sound bizarre to some, but it could work. When I was working at a radio station, we presenters would have different feeds into each ear. One would have the station output running (golden rule in radio ALWAYS listen to station output), the other would hear comms from others in the studio and/or cueing up the next trackto be played. (It is all done by computer now). So it is perfectly feasible to hear (not necessarily listen) to two outputs at once. However whether one would have the capacity to absorb the info without becoming confused. Remember Aviate, Navigate, Communicate in that order.
If you are determined to try it why not just do as you suggest and slide one of the mini earphones up inside your main headset, you only need one channel. so one of those you useed to get with cassette players might do the job.
Last edited by Dawdler; 16th May 2011 at 18:52.
Reason: added a bit.