I'm not sure if this a bug or a new addition, but I had normal nichelings (no ancient genes) spawn from ice blocks. It happened to me twice, and both times they had wings and the platypus beak, instead of any ancient genes.
I had two normal nichelings coming from iceblocks. I mean they had wings and the platypus beak so they had rarer genes but they still didn't have any trace of the ancient genes ... Now that could be a bug on the tester branch, but I had it happen. I only got one ancient gene from an iceblock so far.
I like this idea. I mean we already have a gene for blindness, so it'd be nice if we had an equivalent for the ear genes.
Deaf people are usually very visually oriented so maybe add +2 seeing and +1 smelling to the deaf ears? Because the blind eyes give +2 smelling and +1 hearing, so the deaf ears could give a bonus to seeing instead.