It's worth noting that since this thread was posted 2 years ago, we've had a little bit of official lore come out about au ra horns.
TL;DR: They're hollow, they don't shed, they grow back if severed, and they provide average hearing ability.
We also were able to see in Stormblood NPC's the way horns grow from childhood, to adulthood, to old age:
Las Vegas FanFest 2016 Lore Panel Wrote:Q: Tell us about Au Ra a little more! How likely is it that their horns and tails are damaged/removed? Do they feel sensation against them, or are they a solid material? Should said tails or horns be damaged, do they grow back or are they lost forever? Just how good is Auri hearing? I'm assuming that the horns are hollow.
A: More info in the lore book, but also: it's hard for a tail or horn to be removed. They don't shed. They grow continuously until they reach a certain size then stop. They don't grow super long. If they're damaged, in a fall or in battle, they will slowly regrow until they reach the maximum size again. The horns themselves are hollow and the vibration of sound inside them aids their hearing. Is their hearing better than a lalafell who are supposed to have the best hearing? No their hearing is about as good as a hyur, just in a different way / hear it / process it differently. More in the lore book!
TL;DR: They're hollow, they don't shed, they grow back if severed, and they provide average hearing ability.
We also were able to see in Stormblood NPC's the way horns grow from childhood, to adulthood, to old age:
![[Image: 8362db4409.png]](http://puu.sh/xgES2/8362db4409.png)
![[Image: 67f1b323cc.png]](http://puu.sh/xgESy/67f1b323cc.png)
![[Image: tUzrT.png]](https://puu.sh/tUzrT.png)
