So lets have more information about the Gelada (Theropithecus gelada). There are two subspecies that have been described: T. g. gelada and T. g. obscurus. They are found in Ethiopia and restricted to the high grassland. They are widespread throughout their range, which means they are of least concern on the ICUN red list.
The 'wobble' is thought to sound something like a cross between a yodel and a baby's gurgle. This can be heard on the link (below) for the article on the bbc site. This may show us some link to how speech evolved in our ancestors. The complexitiy of the vocal chords isn't found in any primates bar humans. This 'wobble' along with "lip-smacking" that has been found in some primates could have allowed us to speak.
The question that I find myself thinking is that do you think that if we hadn't evolved the ability to speak and communicate properly with each other. would we be where we are now? Would we have evolved another way to communicate? A thought to ponder on.
References:
http://www.bbc.co.uk/news/science-environment-22067192 (News Story)
http://www.cell.com/current-biology/retrieve/pii/S0960982213002091 (Actual paper)
http://www.iucnredlist.org/details/21744/0 (ICUN Red List on the Gelada Baboon)
