This question is about the horns, and hearing abilities, of the Au Ra!

I read somewhere that Au Ra horns are hearing apparatus, since they appear to replace their ears - is this true? Since the structures are to sense vibrations in the air, would this make them sensitive, or even painful, if touched? Would a horn being struck stun or disorientate an Auri individual, or do they have failsafes against overstimulation of this kind? If they aren't born with fully-developed horns, would this mean that Auri babies are without the ability to hear until their horns grow in? Would some horn shapes be better for hearing than others - e.g. broader, more diagonal horns would be better than thin, horizontal ones? Some of the hairstyles available have smaller horns on the top of the head - would these also contribute to hearing, or would they be closer to traditional horns? Are there any associations or superstitions among the Auri peoples as to what these "extra" horns mean?