It is a question that many have asked (well, in film at least): What would happen if a chimpanzee could say “No”? Previous research suggested their inability to talk was due to limitations in their vocal tract anatomy. Well, new research suggests that it could be more to do with their brains than their mouths, as experiments with macaque monkeys have found that they have the vocal capability, but not the cognitive know-how to speak.
The international team of scientists looked into the vocal capabilities of macaque monkeys by using X-ray videos to record the movements and changes in their lips, tongue, and larynx when making noises. This is a marked change from previous experiments into the vocal abilities of primates, which have tended to use dead specimens to examine their vocal anatomy.
The data gathered from the videos was then fed into a computer model that could simulate the macaques' vocal ability and range based on their physical attributes. They found that the primates possessed the anatomy to produce sounds used in human speech, such as vowels, and would even be able to produce full sentences. The resulting noises are “clearly intelligible” even if they do sound fairly creepy to our human ears.
Listen to what a macaque would sound like asking “will you marry me?” below. Warning: you may not be able to sleep afterward.
This, they claim, means that what is lacking is not the vocal apparatus, but the cognitive ability instead.