So I’m trying to design my alien life around the pressures they might face just like earth’s wildlife, and most things I’ve made plausible life that is similar to ear but not giant dinosaur cats. The problem I’ve come to now is hearing.
There are many, many examples across the animal kingdom of different life exploiting sight, smell and touch as ways to serve their environment, but as I see it the only life that has taken full advantage of sound is mammals (not including monotremes). Nothing else has the characteristic pinna that capture (and amplify) sound and direct it to the inner ear, and even without that mammals internal ear anatomy is more complex than most other life.
In a sci-fi perspective, I have not found non-humanoid alien designs with outer ears. It seems that universally people steer clear of adding ears, as they are a very familiar trait and a design may seem less alien with them. I’m inclined to follow suit for the same reasons as well as simply trying to find an alien alternative.
So far I have designed a rough concept of a creature with closable, fixed intakes (kinda similar to air intakes on a car or jet) to funnel air into the ear canal. My problem with this design is that it misses out on the swivelling advantage of mammals, having the creature need to turn their head to catch the sound.
TLDR, outer ears (pinna) seem to be exclusive to mammals, and so the excuse of convergent evolution is harder to grasp. Is it too earth-like to give aliens ‘ears’ and if not, is there another plausible structure that serves a similar purpose?
Edit: I’ll specify a land-based creature. Aquatic hearing performs under different constraints, pinna are massive sources of drag in that circumstance anyway.