In the vast expanse of the ocean, beneath the gentle sway of waves and the dance of sunlight filtering through azure depths, sperm whales are engaging in a dialogue that has long captivated human curiosity. These oceanic giants, with their intricate social lives and complex communication, embody a world of mystery and wonder that continues to intrigue scientists and researchers.

Among them is Shane Gero, an author of a recent study by Project CETI that used machine learning to decipher sperm whale vocalizations. Gero, the biology lead for Project CETI, discussed this fascinating field of research at the 2023 Bioneers Conference. The project’s recent study, which was published in the journal Nature Communications, identified variations in sperm whale calls that show they are more expressive and structured than previously believed, forming the backbone of a phonetic alphabet. The findings open a window onto the deep underwater world of sperm whales and could be a key to someday deciphering their language. 

Sperm whales are social beings, forming tightly knit communities and bonds that transcend generations. Within their pods lies a society rich in culture and tradition. Long-term studies have unveiled a matrilineal hierarchy, where knowledge and customs are passed down from grandmothers, mothers and aunts to calves, shaping the fabric of their existence.

At the heart of this society is their language, which is made up of short bursts of clicks of varying patterns, known as codas. These sequences of sounds are the threads that bind sperm whales together, conveying a wealth of information that scientists have been observing, recording and cataloging for decades. But until now, researchers have been able to take only baby steps toward anything remotely close to comprehension. 

The new findings from the purposefully broad and interdisciplinary team of scientists gathered together by Project CETI are providing tantalizing glimpses of progress toward a deeper level of understanding. By using machine learning to analyze thousands of sperm whale calls, researchers found that variations in the codas were contextual rather than random, forming the basis of a phonetic alphabet capable of complex communication. The findings challenge previous notions about the simplicity of sperm whale communication and the paradox it represented. 

The Paradox of Sperm Whale Communication

Complex societies, whether among human or non-human species, typically depend on advanced communication systems to navigate intricate social dynamics, including tasks such as strategizing and teaching. In the case of sperm whale societies, where researchers have documented cooperative hunting and foraging strategies, the transmission of intergenerational knowledge, and cultural diversity among pods, one would expect the complexity of their communication to parallel the sophistication of their collective behaviors.

However, despite a wealth of knowledge regarding sperm whale behavior and social dynamics, researchers have encountered a puzzling paradox regarding their communication systems. While the societal complexity of sperm whales hints at a rich and nuanced language akin to human languages, historically, researchers have not been able to identify the same level of complexity within sperm whale vocalizations. 

This discrepancy has raised questions about the nature of their communication and the potential existence of undiscovered layers of complexity within their vocalizations. Unraveling this enigma promises to shed light on the intricate world of sperm whale communication and deepen our understanding of the parallels between human and non-human intelligence.

Deciphering the ‘Sperm Whale Phonetic Alphabet’

The study by Project CETI, which utilized recordings from the Dominica Sperm Whale Project, reveals a fascinating complexity within sperm whale communication — one that is much more in line with what would be expected of a complex society. The study illuminates a previously unseen depth in sperm whales’ vocal repertoire.

By analyzing the different codas, or click patterns, of the Eastern Caribbean sperm whale clan, the researchers were able to identify specific variations in the codas. For any given coda, the whales might slow the clicks down, speed them up, or add an extra click or clicks on the end.

With the ability to analyze thousands of codas, the project leveraged machine learning to discover that rather than being random, the variations were sensitive to the conversational context in which they occurred. In short, the codas give the sperm whales their own phonetic alphabet, and with it, the ability to convey meaning. Just as humans can combine the same sounds in different patterns to create various words and meanings, the codas represent a tool the whales could use to describe their world. 

As we continue to learn more about the mysteries of the ocean and its inhabitants, the symphony of sperm whales serves as a reminder of the vastness of life forms and their unique methods of expression. The journey to decode their language is far from over, but with each new insight, researchers inch closer to unraveling the depths of connection and communication among these oceanic giants.

Shane Gero, one of the report’s authors, has recently discussed Project CETI’s sperm whale research with the Bioneers audience in these fascinating discussions:

• Shane Gero – Preserving Animal Cultures: Lessons from Whale Wisdom (VIDEO)
• What Sperm Whale Communication Can Tell Us About Communities & Cultures Beneath the Ocean’s Surface (ARTICLE)
• Deep Listening: Whale Culture, Interspecies Communication, and Knowing Your Place (PODCAST)