Mangabeys have a special throat sac that gives them a booming voice. Males have larger throat sacs than females. They make shrieking alarm calls, barks, twitters, and grunts. Adult male mangabeys make a whoop-gobble, which is a unique vocalization that catches the attention of other mangabeys in the area and tells them who and where an individual is. It can be heard up to 1,000 yards away.