Apes are unlikely to become virtuosos at the opera house, but gibbons have naturally mastered some of the vocal techniques that human sopranos rely on, scientists in Japan report.
The research, published today in the American Journal of Physical Anthropology, shows that, like humans, gibbons use a ‘source–filter’ mode of sound generation.
The sound originates from the creatures’ vocal folds as a mixture of different harmonics, which are multiples of the frequency at which the vocal folds vibrate. The resonant frequencies of the vocal tract then determine which of these harmonics are projected. By altering the position of the mouth, lips and teeth, humans vary these resonant frequencies to make the different sounds required for speech.
Checkout the article on Nature to learn more about the research and listen to a recording of ‘Gibbon Calls on Helium’.