I myself hear three out-of-odd sounds - firstly, the horse whinny, second, a high shrill (could be wind, but no wind could ever sound like the shrill voice I keep hearing), and lastly, growls which do not at all sound like Bahamut's growls. Personal theory is that those were the sounds of Odin, Shiva and Fenrir respectively, with the hypothesis that those primals who have yet to be defeated and banished also joined in the scene. Ramuh's beard and Leviathan's fins can't exactly produce, sounds can they.
