My understanding of binaural recording is that it is intended as an improvement on conventional stereo recording, giving more realistic spatial imaging. Given the nature of a concertina, with sound coming out of the ends in opposite directions, I am somewhat bemused as to the virtue of any sterophonic imaging at all. With a Duet, or with an Anglo if playing mostly melody on one end and chords or harmonies on the other, a case could be made for allowing the listener to hear the two ends separately. With an English, or with an Anglo played in the Irish style, don't you want all the notes to seem to come from roughly the same place?