Four ears?

drferox:

Anonymous said: (1/1) How do you think the hearing of people with both human
ears and animal ears (let’s say cat ears) would be affected by having
two sets of different ears? Would there be any kind of hearing related
advantage or disadvantage? (I totally understand if you’d like to save
this for a fantasy biology post or some such)

There’s not actually a lot to base this on, as there isn’t a vertebrate species in nature that has four ears. There are some individuals born with four external pinnae (the outer bit of the ear that we pat and think is adorable) but they don’t have four inner ears, ear drums, etc. So I don’t have much in the way of real-life examples to base this off.

I can only assume that there is no advantage to having four ears, or evolution would have thrown us an example by now.

And really, what sort of advantage is a human ear going to offer anyway? These small, barely mobile, sad little flat things that do a bare minimum job compared to, in your example, cat ears, which are much more precise at pinpointing sound and able to move in independent directions.

So why would we have two sets of ears when one is capable of doing everything that the other set does, and more? At best the second set is superfluous.

Unless you’re going to claim the second set offers advantages in perceiving pitch or ultrasound, but then why not modify the singular set to allow it to do that too?

One disadvantage of having who sets of ears is that you need physical space on the head to accommodate them, and the associated ear canal, entry to the brain for cranial nerves and muscles to move them. There’s only so much space on a head, so this starts to get rather awkward. 

Unless you’re going to claim they are purely cosmetic, in which case they’re not offering an advantage anyway, except perhaps in mate attraction.