My name is Aodhán. The pronunciation can be completely different from one dialect to another. That being said, I know how to pronounce my own name and most people, in Dublin at least, have it down pretty well.It is pronounced AY-DAWN, except there is no hard D sound in -DAWN. It is a soft D that is very much like the TH in there, the, then, etc.
I have heard this name pronounced both ay-AWN and ay-DAWN. The differences in pronunciation could be because of the differences in pronunciation between the provinces of Ireland. Personally, though, I like ay-AWN better.