This technique shouldn’t work well for one ear only, but it might help work out the general direction of the calls by the enhanced difference in volume depending on the direction it’s pointed in. A more directional microphone might help more, but he would have to wave it around to find the loudest direction by trial and error.
I haven’t got very good high range hearing either. It’s interesting to listen to the recordings later and see high frequencies on the sonograms and wonder what they were (and still not necessarily be able to hear them).
Peter Shute
