Thrik, I'm no audio engineer but the best way I can describe it is some kind of mix of a synthesized horn or brass instrument washed out (ie, dominated by) a grinding type of static. MW3 and BF3 both used variations on this kind of tone, as did Inception as mentioned above. My "horn or brass instrument" inclusion could be totally off, but I get the trend Minos and Mazy are talking about.
Otherwise, yeah Mazy I would add a W in it so it would be "BWHHHAAAA" or something.
Might want to listen to other recent Hans Zimmer work...such as the Christopher Nolan Batman movie soundtracks. They get some industrial type sounds in there, as well, and since he did the Inception soundtrack (wait, didn't he?) it's just starting to paint a broader picture of the trend.