@article {310984,
	title = {Vocal fold control beyond the species-specific repertoire in an orang-utan},
	journal = {Scientific Reports},
	volume = {6},
	year = {2016},
	month = {07/2016},
	pages = {30315 - },
	abstract = {<p>Vocal fold control was critical to the evolution of spoken language, much as it today allows us to learn vowel systems. It has, however, never been demonstrated directly in a non-human primate, leading to the suggestion that it evolved in the human lineage after divergence from great apes. Here, we provide the first evidence for real-time, dynamic and interactive vocal fold control in a great ape during an imitation {\textquotedblleft}do-as-I-do{\textquotedblright} game with a human demonstrator. Notably, the orang-utan subject skilfully produced {\textquotedblleft}wookies{\textquotedblright} {\textendash} an idiosyncratic vocalization exhibiting a unique spectral profile among the orang-utan vocal repertoire. The subject instantaneously matched human-produced wookies as they were randomly modulated in pitch, adjusting his voice frequency up or down when the human demonstrator did so, readily generating distinct low vs. high frequency sub-variants. These sub-variants were significantly different from spontaneous ones (not produced in matching trials). Results indicate a latent capacity for vocal fold exercise in a great ape (i) in real-time, (ii) up and down the frequency spectrum, (iii) across a register range beyond the species-repertoire and, (iv) in a co-operative turn-taking social setup. Such ancestral capacity likely provided the neuro-behavioural basis of the more fine-tuned vocal fold control that is a human hallmark.</p>
},
	url = {http://dx.doi.org/10.1038/srep30315},
	author = {Lameira, A. R. and Hardus, M. E. and Mielke, A. and Wich, S. A. and Shumaker, R. W.}
}
