This from the paper's abstract: Finally, we control for whale movement and present several pieces of evidence suggesting that the observed patterns are not arti

This from the paper's abstract: Finally, we control for whale movement and present several pieces of evidence suggesting that the observed patterns are not artifacts, but are actively controlled by sperm whales. We also show that the two coda vowels (the a-vowel and i-vowel) are actively exchanged by sperm whales in dialogues. The uncovered spectral properties suggest that codas are highly compositional, more informative, and more complex than previously thought. This from the article: “If our findings are correct, it means that the communication of sperm whales is much more complex and can carry more information than previously thought,” the researchers concluded. The researchers here make two observations, the whales intentionally use specific forms in their songs and the specific forms are sequenced differently but intentionally. For biologists this is significant because it differs from a common form of "singing" or "calls" that each have a specific meaning but they are not internally variegated like these calls are. What the researchers propose (or hypothesize) is that this intentional and varied voicing within a "song" suggests the whales are exchanging much more detailed information than "threat" or "help" or "food here" etc.