The problem with that is that ,as human ,we already subconciously know the gender of other human ,but we can easily be fooled by our own eyes/ear/touch/scent ,but you will always feel that something is weird compared to what your senses are telling you ,not matter how small it may be . (Of course it doesn't work through a screen ,you need to be present irl next to them ,to have the subconscious feeling)