The best way I know how to tell you when open mouthed hounds are bayed is this way: If you had an adjustment knob for the 'intensity' of their bark when they're trailing a hog.....turn it up several notches and that's what they sound like bayed. It's not hard to tell at all. As halfbreed said.....some bawl on track, some bawl when bayed, some chop when trailing and some chop when bayed. The guy I hunt most with has a young male Plott that sounds like he's looking at the devil when he's baying.....he sounds just like most dogs do when they're 'booger barking',......thus his name is Booger. If you wish to here a truly sweet hound bay.....go to this link.....
http://www.youtube.com/watch?v=QBs7T_3Hx_k....it doesn't get any better than this if you're a hound man.