Scientists believed that the ability to produce sounds and vocalizations in various emotional states before the development of language is only unique to human infants however, new research reveals that chimpanzees can also produce these baby sounds.
Wild bonobos that are also the closest primate relatives of humans can apparently vocalize in a similar manner the way babies do usually by a squeaking sound called "peep" that is usually expressed by baby bonobos to be understood by their mother. These peeps are high pitched sounds that are produced with a closed mouth occurring in short durations.
Scientists from the University of Birmingham and the University of Neuchatel have carried out a research on bonobos while they are in their native habitat in Congo. Researchers have discovered that the bonobos use this "peep" during many situations that could be positive, negative or neutral without any differences in acoustic structure which means the listener should be able to interpret what context the baby bonobo is trying to communicate.
According to lead author of the study, Zanna Clay from the University of Birmingham's School of Psychology, these peeps made by baby primates are frequent in nature which could mean many different contexts depending on the situation. It was made apparent that the peeps are difficult to decipher from one another where further study is needed to understand the context to obtain the root of this communication.
Researchers discovered that the peeps that were produced during negative contexts are distinct in acoustic tone where they believe is made with higher subglottal air pressure during the baby's call. Negative situations often entail tension and urgency that can alter their vocal tones.
These new findings now offer new insight about how animal sounds and vocalizations can also imply specific contexts or convey a certain emotional state that suggest that functional flexibility or the ability to produce sounds in different contexts before language development, also have evolutionary origins that existed before human speech.
This new study is published in the journal, Peer J.