WIKIMEDIA, ZYANCEAn orangutan named Rocky impressed scientists at Durham University, in the U.K., by mimicking more than 500 vowel-like sounds in human speech, the researchers reported today (July 27) in Scientific Reports. It’s the first time a nonhuman primate has demonstrated this level of vocal fold control, hinting out how humans evolved speech after they split off from great apes.
The long-held notion that great apes lack this ability can now be thrown “into the trash can,” study coauthor Adriano Lameira of Durham University told BBC News.
Lameira and colleagues trained Rocky to produce vowel sounds that mimicked the pitch and tone of human speech. The researchers compared Rocky’s vocalizations with a database of thousands of hours’ worth of calls of wild and captive orangutans, finding that Rocky was able to control his voice in novel ways and learn new sounds.
“Notably, the orangutan subject skillfully produced ‘wookies’—an idiosyncratic vocalization exhibiting a unique spectral profile among the orangutan vocal repertoire,” the researchers wrote in their paper. The findings could help explain how humans evolved the sophisticated control of their voices that allowed them to develop speech, the team added.
Lameira and colleagues previously described a female orangutan named Tilda in a German zoo that was able produce sounds with the same rhythm and pace as human speech, New Scientist reported.