Vocal signals often play an important role in synchronizing the activities of group members, coordinating decisions about when and where to travel, and facilitating social interactions in which there are potential conflicts of interest. In chacma baboons, Papio ursinus, low amplitude grunts facilitate nonaggressive social interactions and reconcile conflicts. Grunts seem to function as signals of benign intent and reduce uncertainty about the signaler's subsequent behavior. Here, we replicate and extend these findings in another species of savanna baboons, the olive baboon, Papio anubis. As in chacma baboons, female olive baboons are more likely to grunt as they approach lower ranking females than as they approach higher ranking females and are less likely to grunt as they approach their own mothers and daughters than as they approach other females. Taken together, these data support the hypothesis that baboons modify their call production for different listeners in different social contexts, and support the view that the mechanisms underlying call production may overlap with the mechanisms underlying call perception.