More than ten hours of young chimpanzee vocalisations have been catalogued, digitised and posted online as described in Scientific Data this week. Many researchers are interested in chimpanzee vocal communication, both as an important aspect of chimpanzee social behaviour and as a source of insights into the evolution of human language.
One of the most striking ways in which human language differs from the vocal communication of primates is the extent to which vocal signals are learned, rather than innate. Recent studies, however, have found evidence of aspects of chimpanzee vocal communication that resemble features of human language, such as referential signalling and regional dialects.
The largest dataset of audio recordings from free-living, immature chimpanzees was collected by the late Hetty van de Rijt-Plooij, and Frans Plooij at Gombe National Park, Tanzania from 1971 to 1973. The audio tapes feature the “grunts”, “hoocalls”, “barks”, “squeals” and other vocalisations of 17 young chimps. These recordings have not yet been analysed, meaning that the most extensive attempt to understand chimpanzee vocalisations remains unfinished.
In order to make this dataset available to more researchers, the analogue sound recordings have been digitized and stored in the Macaulay Library and released into the public domain via the Dryad Repository online, along with the original notes on the contexts of the calls which have been translated from Dutch into English.