I haven’t watch this show in a long time, so I don’t know what Carl’s voice sounds like. But it seems to me that if Carl was raised by Icelandic parents, his voice should be indistinguishable from white persons – or rather, he should have a Scandinavian accent of some sort, which would be pretty hard to find in a black voice-actor. The black voice-actor would have to “do” the voice, just as Hank Azaria had to do the voice of Apu. And as no one can see the voice-over actor it really doesn’t make much sense to insist the actor should be black. It implies that there is something genetic in Black people which makes it impossible for a white person to do any Black person’s voice, which seems racist to me.

I don’t think this is a big deal. It’s just a rather silly consequence of certain political assumptions, which are otherwise worth accepting .But I think it’s worth thinking about.