Baby in the Jungle? Nope, They're Just Bonobo Apes Creating Human Infant Sounds

A new study revealed that bonobo apes have the ability to make human infant sounds as a means of communicating. The sounds were recorded from wild bonobos located in the Congo Basin.

Researchers from the University of Birmingham in the United Kingdom and the University of Neuchatel in Switzerland, discovered that bonobos made high-pitched sounds in the same manner as human babies. Generally, primates or other animals only create sounds that refer to their current emotional state or particular events. Animals might call out when they get excited over food or spot a predator coming. The study was published in the journal PeerJ.

The great apes, however, made sounds in different circumstances. These made high-pitched “peep” calls even in neutral situations. The primates would sound off when moving or eating, showing that regardless of their emotional state, they will make sounds. These were the same as “protophones” or sounds made by human infants before they develop the ability to speak, based on a report by NBC News.

The “peep” calls may suggest a bridge between human speech and functionally fixed animal vocalizations. The bonobo apes also made other sounds like grunts, pants and barks. The sounds, although seemingly simple, present a huge connection between animal sounds and human speech.

Zanna Clay, a psychology researcher at the University of Birmingham, said that the sounds made by the primates appeared very flexible. She shared that they collected recordings of peeps made in various contexts. They found that peeps made during neutral or positive situations were acoustically identical. On their own, the peeps do not link very strongly to a single definition. As for negative situations, the acoustic frequency was slightly different. The bonobo apes used such sounds during periods of perceived danger or distress. The animal kingdom features various sounds that come out in different contexts.

“Our capacity for this type of flexible signaling was probably a much older capacity than just the human lineage,” Dr. Clay said.

"We felt that it was premature to conclude that this ability is uniquely human, especially as no one had really looked for it in the great apes. It appears that the more we look, the more similarity we find between animals and humans,” Dr. Clay added.

The new results pushed back the development of context-free vocal calls to the shared ancestry of humans with bonobos about 6 to 10 million years ago, based on a report by Radio New Zealand.