Scientists have spent decades attempting to communicate with dolphins, and researchers believe they may have identified a suitable model for deciphering the cetaceans’ high-pitched calls. In a new study published in Frontiers in Psychology, they explain how whistled human languages may share certain fundamental attributes with dolphin signals, and that studying the two side-by-side could yield valuable insights into how dolphins communicate.
To be clear, the authors are not suggesting that the nature of the information encoded in dolphin whistles matches that of human language. Rather, they propose that “the way information is structured in whistled speech may inspire research on dolphin whistled communication.”
This theory stems from the fact that human and dolphin whistles “are characterized by similar acoustic parameters and serve a common purpose of long distance communication in natural surroundings in two large brained social species.”
According to the researchers, whistled languages are currently used by around 80 cultures worldwide, typically to relay information to people out of earshot. These whistled dialects transform spoken language into a non-verbal form. This makes them interesting to scientists studying how other highly intelligent species communicate without words.
Pointing to several previous studies, the authors explain how bottlenose dolphins have displayed certain cognitive attributes that are considered fundamental to human communication. For example, they are able to comprehend whistles that have been distorted by noise pollution, demonstrating an ability to extrapolate meaning from partial cues in much the same way that humans do.
Furthermore, they appear to utilize so-called “phatic expressions”, which contain no actual information but merely serve to establish contact. In human terms, these signals may be seen as the equivalent of saying “hello”, the authors explain.
However, in spite of these intriguing similarities, many key elements of dolphin communication remain a complete mystery. For instance, the researchers point out that deciphering the animals’ calls will likely remain impossible until we develop an appreciation of the “smallest meaningful units of sound” utilized by dolphins.
In human linguistics, for example, the smallest unit of sound that can be used to alter the meaning of a word is known as a phoneme. For example, the words “hand” and “band” differ by a single consonant, yet have very different meanings.
To determine how dolphin whistles are distinguished, the researchers now propose to cross-reference databases of recorded dolphin whistles with human whistled languages. "On these data, for example, we will develop new algorithms and test some hypotheses [regarding the structure of dolphin communication]" explained study author Julien Meyer in a statement.
Before these algorithms can be developed, however, Meyer insists that “we would need to know what the minimum unit of meaningful sound is, how they are organized, and how they function.”