Aodh on it's own is proounced 'ay' in bay (The anglicisation is Hugh). án is awn. So it can be pronounced Ay-dawn (more common) or Ay-awn, as usually in old names the 'dh' isn't pronounced. E.g. Cliodhna is Clíona - Clee-oh-naAiden is the anglicisation of Aodhán.