I think there's something to the hearing. Some of my friends speak other languages and I'll try to repeat something but apparently I'm speaking gibberish because my pronunciation is so bad, but I simply cannot hear the difference. I've heard comedians make this joke about English speakers trying to speak Chinese too.

I think there's a similar thing with faces. I knew some identical twins in school and at first I couldn't tell them apart, but after seeing them a bunch it became instant. I think it's similar with facial recognition of races we don't see often.

So yeah, something about repetition until you can spot the difference seems to be beneficial.