I have white chinese, african, and embden. The voice thing works very well with my chinese and the africans and the embdens are new to me and I haven't got a clue with them. I hear differences in their voice, but since I can't even distinguish individual birds yet - it is all a mystery to me. I sit and watch the flock of ten geese and look at their heads, thier undersides, and listen to them and can only guess which is which.