Speech-like vocalizations in our primate cousin - the Gelada

One of the difference between humans and other primates is our wide range of vocalizations - which we exploit in our use of  an extensive spoken language. Recent work by Thore J. Bergman of the University of Michigan on the Gelada (a baboon species) show that it makes a "wobble" like noise that has some has some similarity to human speech.  There are also some other references to lip-smacking as a means of signalling in primates.

Speech-like vocalized lipsmacking in geladas, Thore J. Bergman, Current Biology Vol 23 No 7