The parties often refer to the result of the negotiation as a collective bargaining agreement (CBA) or as a collective employment agreement (CEA).
When theyâre happy and satisfied they make a humming sound. This sounds like a blend of buzzing and humming. When in danger alpacas will sound an alarm which sounds a little like a horseâs whinny. And, as you now know, before mating alpaca stallions âorgleâ.
1 They hiss - sounds much the same for most species, with a few exceptions. The sound a rearing Indian Cobra makes, for example, sounds like a muffled sneeze.  They have a sound producing organ - the obvious example of this is the North American rattlesnake.