Researchers in Japan have discovered that one of the apes common in Asia uses the same techniques as soprano singers when they make their calls through the jungle. A team working at Kyoto's Primate Research Institute has used a surprising experiment.
Reportagem: Jason Palmer
Humans have vocal folds very similar to those of apes, but we can also precisely control the shape and size of our vocal tract. For powerful high notes, soprano singers match the natural frequencies of the two.
But how to find out if gibbons can do the same? Give them some helium. Helium raises the natural frequency just of the vocal tract but not the vocal folds. In helium-huffing gibbons, calls stayed just as piercing because the animals tuned their vocal tracts to match the higher frequencies. In short, gibbons sing soprano all the time.
It's not just a primate party trick - this separation between the actual source of the sound and the mechanism of shaping it is something that biologists thought was a result of a long evolutionary process, leading to our finely-controlled speech. But it seems nature came up with the biological equipment for these techniques long before humans headed to the opera.
vocal folds (cordas vocais): tissue in the throat that is moved by air to produce the voice
vocal tract (trato vocal): passages in the nose, mouth and throat where air moves to produce the voice
soprano singers (cantoras soprano): people who sing with the highest voice
frequencies (frequências): rates at which sounds vibrate
helium (hélio): chemical element often used to make balloons float
piercing (perfurantes, fortes): high and loud
tuned (ajustado): adjusted
party trick (truque, algo engenhoso e divertido): amusing performance at a party
mechanism (mecanismo): system or method
finely-controlled (algo controlado com precisão): carefully produced